ORTEC DSPEC Hardware Manual

69;,*
®
DSPEC®
Digital Gamma-Ray Spectrometer
Hardware Manual
Printed in U.S.A.
ORTEC Part No. 761560
Manual Revision G
0303
$GYDQFHG0HDVXUHPHQW7HFKQRORJ\,QF
a/k/a/ ORTEC®, a subsidiary of AMETEK®, Inc.
WARRANTY
ORTEC* warrants that the items will be delivered free from defects in material or workmanship. ORTEC makes no other
warranties, express or implied, and specifically NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE.
ORTEC’s exclusive liability is limited to repairing or replacing at ORTEC’s option, items found by ORTEC to be defective
in workmanship or materials within one year from the date of delivery. ORTEC’s liability on any claim of any kind, including
negligence, loss, or damages arising out of, connected with, or from the performance or breach thereof, or from the
manufacture, sale, delivery, resale, repair, or use of any item or services covered by this agreement or purchase order, shall in
no case exceed the price allocable to the item or service furnished or any part thereof that gives rise to the claim. In the event
ORTEC fails to manufacture or deliver items called for in this agreement or purchase order, ORTEC’s exclusive liability and
buyer’s exclusive remedy shall be release of the buyer from the obligation to pay the purchase price. In no event shall ORTEC
be liable for special or consequential damages.
Quality Control
Before being approved for shipment, each ORTEC instrument must pass a stringent set of quality control tests designed to
expose any flaws in materials or workmanship. Permanent records of these tests are maintained for use in warranty repair and
as a source of statistical information for design improvements.
Repair Service
If it becomes necessary to return this instrument for repair, it is essential that Customer Services be contacted in advance of
its return so that a Return Authorization Number can be assigned to the unit. Also, ORTEC must be informed, either in writing,
by telephone [(865) 482-4411] or by facsimile transmission [(865) 483-2133], of the nature of the fault of the instrument being
returned and of the model, serial, and revision ("Rev" on rear panel) numbers. Failure to do so may cause unnecessary delays
in getting the unit repaired. The ORTEC standard procedure requires that instruments returned for repair pass the same quality
control tests that are used for new-production instruments. Instruments that are returned should be packed so that they will
withstand normal transit handling and must be shipped PREPAID via Air Parcel Post or United Parcel Service to the designated
ORTEC repair center. The address label and the package should include the Return Authorization Number assigned.
Instruments being returned that are damaged in transit due to inadequate packing will be repaired at the sender's expense, and
it will be the sender's responsibility to make claim with the shipper. Instruments not in warranty should follow the same
procedure and ORTEC will provide a quotation.
Damage in Transit
Shipments should be examined immediately upon receipt for evidence of external or concealed damage. The carrier making
delivery should be notified immediately of any such damage, since the carrier is normally liable for damage in shipment.
Packing materials, waybills, and other such documentation should be preserved in order to establish claims. After such
notification to the carrier, please notify ORTEC of the circumstances so that assistance can be provided in making damage
claims and in providing replacement equipment, if necessary.
Copyright © 2003, Advanced Measurement Technology, Inc. All rights reserved.
*ORTEC® is a registered trademark of Advanced Measurement Technology, Inc. All other trademarks used herein are the
property of their respective owners.
TABLE OF CONTENTS
Safety Instructions and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Cleaning Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1. What is DSPEC? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2. About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. GETTING STARTED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1. What You Will Learn in this Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2. The Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3. The Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4. Internal Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5. Internal Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
3
3
4
5
8
3. SYSTEM CONNECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. What You Will Learn in this Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2. Building a System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.1. Single-Detector Non-Networked System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.2. Multiple Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2.3. Multiple Computers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4. THEORY OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1. What You Will Learn in this Chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2. Review of the HPGe System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3. The Shaping Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4. Analog vs. Digital . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
11
11
11
12
5. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1. System Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1. Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.2. Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.3. Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.4. Interface Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2. Electrical and Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.1. Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.2. Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
15
17
18
19
19
19
20
20
20
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DSPEC® Digital Gamma-Ray Spectrometer
6. COMMANDS AND RESPONSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1. Command Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2. Percent Response Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3. Dollar Response Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4. Command Catalog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
21
22
24
24
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
iv
Safety Instructions and Symbols
This manual contains up to three levels of safety instructions that must be observed in order to
avoid personal injury and/or damage to equipment or other property. These are:
DANGER
Indicates a hazard that could result in death or serious bodily harm if the safety
instruction is not observed.
WARNING Indicates a hazard that could result in bodily harm if the safety instruction is not
observed.
CAUTION Indicates a hazard that could result in property damage if the safety instruction is
not observed.
In addition, the following symbols may appear on the product:
DANGER–High Voltage
ATTENTION–Refer to Manual
Please read all safety instructions carefully and make sure you understand them fully before
attempting to use this product.
Cleaning Instructions
To clean the instrument exterior:
Disconnect the instrument from the power source.
Remove loose dust on the outside of the instrument with a lint-free cloth.
Remove remaining dirt with a lint-free cloth dampened in a general-purpose detergent and
water solution. Do not use abrasive cleaners.
CAUTION To prevent moisture inside of the instrument during external cleaning, use
only enough liquid to dampen the cloth or applicator.
Allow the instrument to dry completely before reconnecting it to the power source.
v
vi
1. INTRODUCTION
ORTEC’s DSPEC (pronounced D–Spec) is an industry first — the first integrated, digitalsignal-processor-based, digital gamma-ray spectrometer for use with all types of germanium
detectors, including super-large detectors.
DSPEC combines all the best features of low- and high-rate analog systems in a single, PCbased package that is easily connected to local area networks (LANs). This highly automated,
yet flexible, hardware and software combination is suitable for most spectroscopy applications.
From all sides, environmental measurement through physics research to on-line industrial
measurements, the question has often been posed: “Why can’t one system provide the best in
resolution, throughput, and stability simultaneously? Why do we always have to make a lessthan-ideal compromise when the detector itself is capable of more performance?” Until now,
these questions have remained unanswered. Now DSPEC provides those answers:
In Environmental Counting, DSPEC provides extremely high stability over long counting
times. DSPEC solves the ballistic deficit problem that often degrades the resolution of large
HPGe detectors. It delivers the best resolution of which any detector is capable. A statistical
preset optimizes sample throughput, and delivers lower cost per sample.
DSPEC is highly automated, ending forever the need to use screwdriver or oscilloscope to
achieve the best performance.
Recognizing that not all counting rooms provide “laboratory conditions,” DSPEC also
provides unprecedented temperature stability for varying ambient temperature.
For applications involving high or widely varying count rates — such as intermediate-level
waste measurement or post accident sampling — DSPEC has unmatched count-rate stability
in both peak position and resolution.
For industrial applications and when LANs are a requirement, DSPEC’s built-in Ethernet
port allows direct connection to the network. No other integrated instrument can do this.
Those wanting to wring the last drop of resolution performance from their detector will
appreciate the built-in InSight™ “Virtual Oscilloscope.”
DSPEC is a truly unique package, providing real benefits “where it counts,” for all gamma
spectroscopy operations: STABILITY, RESOLUTION, and AUTOMATION.
1
DSPEC® Digital Gamma-Ray Spectrometer
1.1. What is DSPEC?
One germanium or silicon gamma or x-ray detector, one PC, and one DSPEC comprise a
complete spectroscopy system. The detector provides a signal proportional to the gamma-ray
energy; the PC provides the user interface, data display, and storage; and the DSPEC provides
everything else.
DSPEC includes an analog prefilter, fast digitizing circuits, and digital signal processing to
optimize energy resolution and data rate, via variable rate baseline restoration, automatic pulse
pile-up rejection, automatic pole-zero cancellation, ballistic deficit correction and zero effectiveconversion-time peak detection, measurement, and storage. Spectral data is maintained in the
DSPEC battery-backed data memory until transferred to the PC by the user. DSPEC also
includes the high-speed data link to the PC, with a choice of ORTEC’s ultra-fast, direct DualPort Memory interface or standard Ethernet interface. You can even connect multiple DSPEC
units into networks and control them all from anywhere on the network!
1.2. About this Manual
This manual describes the ORTEC DSPEC Digital Gamma-Ray Spectrometer, and provides all
the information necessary to prepare the DSPEC for use and connect it into a complete
spectroscopy system. Because the DSPEC is almost completely computer controlled, this manual
is short. Details on running the control software are contained in the MAESTRO™ and
GammaVision™ software manuals. A condensed version of some key MAESTRO and
GammaVision information is provided in the ORTEC publication entitled “DSPEC Digital
Gamma-Ray Spectrometer and Its Use with MAESTRO™ or GammaVision™.”
2
2. GETTING STARTED
2.1. What You Will Learn in this Chapter
In this chapter you will:
Become acquainted with the DSPEC front- and rear-panel indicators and controls.
Set the electrical power input for your local conditions.
Learn whether you need to change the factory settings of the internal switches.
2.2. The Front Panel
Figure 1 shows the DSPEC front panel.
Fig. 1. DSPEC Front Panel.
Starting from the left, there are four LEDs indicating the status of the detector bias supply.
Illumination of the HV ON light indicates that the rear-panel high voltage connector is powered.
Either the HV POS or HV NEG light will be illuminated to show the internal setting of the
detector bias polarity switch.
The OVERLOAD light indicates that the power supply is overloaded and shut down. (This
condition usually indicates a shorted output due to a faulty cable or improper connection.)
The PROCESSOR BUSY light flashes to indicate functions of the internal microprocessor.
3
DSPEC® Digital Gamma-Ray Spectrometer
The STABILIZER GAIN and OFFSET numeric displays indicate the settings of the internal
digital spectrum stabilizer. If the stabilizer is not being used, the displays indicate “off.”
The SPECTROMETER ACCEPT and REJECT lights indicate the operation of the internal
pulse pile-up rejector. If pulses from the detector are too close together in time to be accurately
measured, they are rejected and the REJECT light flashes. Each measured pulse causes the
ACCEPT light to flash.
Additional information on the rate of data acquisition is available from the SPECTROMETER
DEADTIME numeric display. The dead time of the system is the fraction of time that the
system is busy and unavailable to process pulses. As the count rate increases, the number of
events rejected by the pile-up rejector increases and the dead time increases. At 50% dead time,
half of the pulses occur so closely together that they are rejected.
The POWER switch turns the instrument on or off and indicates its status with a lighted
indicator.
2.3. The Rear Panel
Figure 2 shows the DSPEC rear panel.
Fig. 2. DSPEC Rear Panel.
4
2. GETTING STARTED
Under the cooling fan is the power input block, into which is plugged an international standard
AC power cord suitable for local power distribution. A small printed circuit board can be
accessed behind a sliding plastic window. This board can be inserted in four different ways,
allowing you to select 100, 120, 220, or 240 volts. The selected voltage is the only one that can
be read through the window. The correct fuse size, power cord, and voltage setting are supplied
with the instrument.
PREAMP POWER, both ±12 and ±24 volts DC, is provided via a standard 9-pin D-type
connector.
The HIGH VOLTAGE section has three components. A 10-turn potentiometer sets the value of
the detector bias. A BNC connector receives the signal indicating a warmed-up detector,
requiring removal of detector bias. The OUTPUT connector is an SHV-type connector carrying
the detector bias voltage.
The next section has three BNC connectors. The INPUT connector receives the low-level
analog signal from the preamplifier. The ADC GATE connector is an input which can be used
to cause the system to accept or reject a pulse under the control of external electronics. The TRP
INHIBIT is an input used to reject pulses during the reset period of detectors with transistorreset preamplifiers.
CHANGE SAMPLE is a logic output used to control sample changers. SAMPLE READY is a
logic input used to report that the sample changer has completed changing the sample. (Use of
these features requires software support discussed in the software manuals.)
Connection to the computer is by means of either the DUAL-PORT MEMORY 37-pin D-Type
connector or the ETHERNET BNC connector. Most new systems will use the more convenient
Ethernet connection; the Dual-Port Memory method is provided for compatibility with existing
systems. The RS-232-C connector provides a low-speed serial link to the PC and is normally not
used.
2.4. Internal Switches
NOTE If you are using P-type detectors, such as ORTEC’s GEM Series, or if you have
purchased a complete system, you may skip the remainder of this section.
There are two internal settings which must be correctly set for your particular type of detector.
Changing these settings requires removal of the DSPEC cover:
5
DSPEC® Digital Gamma-Ray Spectrometer
DANGER Turn off the DSPEC, remove its power cord, and wait several minutes for the
power supply to discharge before performing this operation!
1. Place the DSPEC upside down on a clean workbench, preferably covered with cloth or clean
paper to prevent scratching the cover.
2. Remove the four Phillips-head screws that secure the cover. There is one screw at each
corner, just outside the rubber feet.
CAUTION The cover is not secured to the chassis; therefore, if the chassis is supported
only by the cover and tilted with the back panel downward, the chassis can
slide free and fall!
3. Carefully place the DSPEC back on its rubber feet.
4. Slide the cover forward to free it from the chassis. Figure 3 shows the internal details of the
DSPEC.
Note the amplifier input polarity switch (note the pointer slightly right of bottom center). This
switch must be set to match the output polarity of your detector’s preamplifier. The factory
setting is positive, which is appropriate for ORTEC GEM detectors and most other P-type
detectors. For those ordering a complete system, the setting will be set correctly during system
checkout.
Changing the detector bias supply polarity is easy to do but not easy to explain:
1. Remove the cover as described above.
2. Turn the DSPEC so that its right side (opposite the power supply and fan) faces you.
3. The high-voltage power supply board is the bottom board in the stack of four boards.
4. Locate the bias selector board (BSB), shown in Fig. 4. The BSB is a printed circuit board
approximately 180 mm × 15 mm. It has eight pairs of jumper pins that plug into the highvoltage power supply board.
The BSB moves one jumper location left or right to select between HPGe detectors or NaI
detectors. The leftmost position is correct for HPGe detectors.
6
2. GETTING STARTED
Fig. 3. Internal Details and Amplifier Input Polarity Switch.
Moving one jumper location from the edge of the board toward the center selects negative or
positive bias. The jumpers closest to the edge of the high-voltage power supply board select
positive voltage; the jumpers toward the center select negative voltage.
5. There are two ways to move the BSB. The easiest way for most people is to place the index
finger of each hand on the ends of the BSB and lift up about one centimeter until the jumpers
clear the board. Move the BSB to the correct set of jumpers and position the jumpers into the
high-voltage power supply board. The BSB can then be completely reseated by pressing
down from the top with your fingertips.
Alternatively, the BSB can be lifted and moved using tools. Two electronics-type needlenose
pliers, one held in each hand, can be used to grip the BSB near each end. Lift and move to
the required jumper position, then position the jumpers with a gentle downward pressure.
Press the BSB completely into place using either the pliers or your fingertips, as above.
7
DSPEC® Digital Gamma-Ray Spectrometer
Fig. 4. Bias Selector Board (BSB).
2.5. Internal Battery
An internal lithium battery provides backup of settings when the power to the unit is off. Should
the battery become depleted, replace it with ORTEC Part Number 739460.
8
3. SYSTEM CONNECTION
3.1. What You Will Learn in this Chapter
In this chapter you will learn how to:
Connect a single-detector/single-computer spectroscopy system.
Add multiple detectors to the basic system.
3.2. Building a System
3.2.1. Single-Detector, Non-Networked System
1. Connect the detector preamplifier power, using the 9-pin D-type connector and the supplied
power cable. The DSPEC provides this power from its rear-panel PREAMP POWER
connector.
2. Connect the detector high-voltage bias. This is usually an SHV-type high-voltage coaxial
connector on the detector preamplifier. The DSPEC supplies this bias voltage from its rearpanel 0–5 kV OUTPUT connector.
3. Connect the bias voltage shutdown circuit. Most cryogenic detectors signal if they are
warming up and should have the bias removed.
CAUTION Detectors can be seriously damaged if this protection is ignored.
4. Connect the Preamplifier Energy Output to the DSPEC rear-panel INPUT connector. The
cable used is normally 100- coaxial cable with BNC type connectors.
5. Connect the data link from the DSPEC to the computer. The normal connection is Ethernet
standard 50- cable with BNC type connectors. Alternatively, the ORTEC Dual-Port
Memory connection can be used. This connection requires that the ORTEC interface card be
installed in your computer. ORTEC can supply the special cable, with 37-pin D-type
connections.
6. Plug in the power and you are ready to take data!
If your detector has a pulsed-reset type preamplifier (ORTEC’s “PLUS” Series), use BNC
coaxial cable to connect the detector’s INHIBIT or RESET output to the DSPEC rear-panel
INHIBIT input.
9
DSPEC® Digital Gamma-Ray Spectrometer
3.2.2. Multiple Detectors
Each DSPEC processes the output of a single detector. If your lab has more than one detector,
multiple systems can be set up as described above. It is usually far more convenient to control all
the detectors from a single computer. This is easy to do with DSPEC-based systems. Using the
Ethernet data link connection method, it is only necessary to chain all DSPECs together into a
single LAN using BNC T-connectors at each DSPEC. (Don’t forget the 50- terminator
required at the last DSPEC in the chain.) ORTEC software handles all the details of finding the
detectors and allowing them to be named individually.
If the Dual-Port Memory data link has been chosen, it is still convenient to connect up to eight
DSPEC controlled detectors (or many other combinations of ORTEC MCBs) to one computer.
The only requirement is a special cable available from ORTEC, plus the standard software.
When more than one ORTEC MCB is connected to a single computer via the Dual-Port Memory
Interface, each MCB in the system must have a unique MCB address. The MCB address for a
DSPEC is set with a jumper inside the unit. To change the jumper setting do the following:
1. Remove the cover of the DSPEC as outlined above.
2. On the inside of the DSPEC, follow the ribbon cable connected to the Dual-Port Memory
connector to the location at which it plugs into the circuit board. The DPM address jumper is
located just behind the ribbon-cable connection point toward the rear of the DSPEC. The
jumper consists of two parallel rows of eight right-angle pins.
3. Move the jumper to the desired address. Address 1 is represented by the two pins closest to
the outside edge of the DSPEC. Address 8 is represented by the two pins closest to the center
of the DSPEC. Figure ? shows the appropriate jumper location for each address.
4. Replace the DSPEC cover.
3.2.3. Multiple Computers
Adding multiple computers is as easy as adding multiple detectors. Using the LAN described
above, multiple computers can control single or multiple detectors using standard Microsoft®
operating systems and ORTEC software. Such systems are cost-effective, redundant, reliable,
and easy to use.
10
4. THEORY OF OPERATION
4.1. What You Will Learn in this Chapter:
Briefly review a high purity germanium (HPGe) gamma-ray spectroscopy system.
Learn how a shaping amplifier controls the tradeoffs between energy resolution and data rate
in an HPGe system.
Compare analog and digital spectroscopy systems.
4.2. Review of the HPGe System
An HPGe detector is a semiconductor diode. Its operation is similar to that of a photodiode
except that it is a few thousand times larger. The detector is operated under reverse bias
(typically a few thousand volts) and at about the temperature of liquid nitrogen. An evacuated
cryostat provides the clean vacuum and low temperature needed by the detector.
When the detector absorbs a gamma-ray photon, electron-hole pairs are created. The resulting
charge pulse is integrated by a charge-sensitive preamplifier to produce a voltage step
proportional to the energy of the gamma ray.
The signal produced by the HPGe detector is very small. A 1-MeV gamma-ray photon produces
a signal of about one-tenth of a volt out of the preamplifier. This small signal must be amplified,
filtered to produce the best signal-to-noise ratio, and measured to a precision of one part in
16,000 in a few microseconds. The amplitude measurement is used to increment the appropriate
element (channel) of an array in data memory. The result of many such measurements is the
spectrum of gamma-ray energies seen by the detector.
4.3. The Shaping Amplifier
The signal produced by the preamplifier must be further processed before being digitized. Three
problems must be addressed:
1. The signals are not referenced to any particular voltage level (such as the system ground) but
instead have a random DC component.
2. Improvements in signal-to-noise ratio can be made by appropriate filtering.
3. The signals are not matched to the range of typical analog-to-digital circuits (ADCs).
The classic solution to these problems is performed by a device called the Shaping Amplifier.
The dc component is removed and low-frequency noise reduced by electronically differentiating
(high-pass filtering) the signal. High-frequency noise is reduced by multiple integrations (low-
11
DSPEC® Digital Gamma-Ray Spectrometer
pass filtering). Variable gain allows matching the range of gamma-ray signals to the range of the
ADC.
The shape and time duration of the shaping amplifier output pulse determine the electronic noise
and maximum data rate of the system. Analog systems typically use a Gaussian shape (like the
standard probability curve) or a modified triangular shape. These perform well, but the optimum
shape has an exponential rising edge, a flattop of duration about equal to the detector rise time,
and an exponentially falling edge with the same time constant as the rising edge. This shape is
referred to as a flattop cusp. Obtaining this shape is very difficult with analog electronics.
There is no advantage to adjusting the time duration of the output pulse to a value longer than
the minimum required. If the optimum duration is too long for the existing count rate, shorter
values are used to allow higher rates accompanied by somewhat degraded energy resolution.
Analog amplifiers typically allow two shapes and 5–10 durations (shaping times).
These systems have been in continuous development for over 30 years. Modern analog systems
include special circuits called baseline restorers to maintain the reference voltage level, and
pile-up rejectors that reject signals that occur so close to another signal that they are distorted.
4.4. Analog vs. Digital
If the output of the preamplifier is sampled at a very high rate by a fast ADC, digital signal
processing can be used to perform all the functions performed by the analog shaping amplifier.
The output of the “shaping amplifier” exists as a sequence of numbers instead of a voltage
signal, but there is an exact equivalence to the analog system. The optimum shape and time
duration are the same. The tradeoff of noise and data rate are the same. The differences,
however, are many:
The digital system can generate the ideal flattop cusp. The shape of the rising and falling
edges (the “cuspiness”) are adjustable to match the detector’s noise characteristics or
improve data rate. The width of the flattop is adjustable to match the rise time.
Changing the shaping time in the analog system involves mechanical switches changing
several components. Consequently, the number of shaping times available is limited. The
shaping time in the digital system is determined by constants in the DSPEC computer code
and can be changed at will. Many more values are available.
The gain in analog systems depends on the value of electronic components and drifts with
temperature and time. Digital systems do not exhibit such changes. As the DSPEC is almost
totally digital, it drifts much less than analog systems.
12
4. THEORY OF OPERATION
The reference baseline in analog systems varies with count rate. This causes peaks in the
spectrum to shift and broaden. Digital systems have no such effects. Again, as most of the
DSPEC is digital, such problems are vastly reduced.
13
DSPEC® Digital Gamma-Ray Spectrometer
14
5. SPECIFICATIONS
5.1. System Performance
DSPEC is unlike analog systems
consisting of discrete components such
as an amplifier or ADC. Whereas it is
conventional in an analog system to
specify the gain instability of the ADC in
ppm/C, in DSPEC many of these
conventional functions are emulated in
the digital world by firmware; therefore,
such specifications are DSPEC SYSTEM
specifications. Comparison should be
made ONLY with SYSTEM
specifications in the analog world.
System Gain 0.35 to 100, continuously
computer-adjustable; minimum gain step
is 1/85,000.
Coarse Gain Computer-selectable as 1,
2, 5, 10, 20, 50, and 100.
Fine Gain Computer-adjustable from
0.35 to 1.00.
Shaping-Time Constants
Rise and Fall 32 rise and fall times
ranging from 0.8 to 25.6 µs in 0.8-µs
steps; computer-selectable.
Flattop 5 flattop times ranging from
0.8 to 2.4 µs in 0.4-µs steps;
computer selectable.
Example of System Conversion Gain
Typical Sensitivities for ORTEC preamplifiers are:
Coaxial
GLP
LO-AX
IGLET
SLP
150 mV/MeV
1.7 mV/keV
300 mV/MeV
3 mV/keV
1.7 mV/keV
DSPEC converts the VOLTAGE output signal from a chargesensitive preamplifier into a count in a memory location of the
histogram memory. This conversion follows the relationship:
Memory Location = Vin × K × Total Gain × Total Channels
where:
Vin is the step-height of the preamplifier signal in volts;
K is a constant equal to (0.855)(total channels)/volt;
Total Gain is the product of the fine and coarse gains;
Total Channels is the total number of channels in the
spectrum.
For example: At 16,384 channels, with the DSPEC set
for a total gain of 2.5, a 200-mV preamplifier signal
(corresponding to a 1.33-MeV gamma ray event in a coaxial
detector) would be stored in:
Channel Location
= (0.2)(0.855)(2.5)(16,384)
= 7004.16
or channel 7004, which corresponds to an overall system
conversion gain of 0.19 keV per channel.
Cusp Parameter (adjusts the curvature of the rise and fall time) 6 values that range from
0.5 to <1; computer-selectable.
Memory Segment Size Computer-selectable as 16384, 8192, 4096, 2048, 1024, or 512
channels full scale.
15
DSPEC® Digital Gamma-Ray Spectrometer
System Conversion Gain The overall gain of the system is appropriate for use with all types of
Ge detectors.
Coaxial “GEM” (P-type) and “GAMMA-X” (N-type).
Low Energy “LO-AX” (low-energy coaxial), “GLP” (planar Ge), “IGLET” and “IGLETX” (ultra-thin window planar Ge), and SLP (SiLi).
Dead-Time Correction Extended live-time correction according to Gedcke–Hale method.1
Accuracy: area of reference peak changes ±3% from 0 to 50,000 counts/s.
Linearity
Integral Nonlinearity <±0.025% over top 99.5% of spectrum, measured with a mixed
source (55Fe @ 5.9 keV to 88Y @ 1836 keV).
Differential Nonlinearity <±1% (measured with a BNC pulser and ramp generator).
Temperature Coefficient
Gain <50 ppm/C. [Typically 30 ppm/C.]2
Offset <10 ppm/C, referred to the input with a total gain greater than 50; rise and fall
times of 16 µs, and flattop of 1.2 µs. (Similar to analog 6-µs shaping.)
Overload Recovery At maximum gain, recovers to within 2% of rated output from X1000
overload in 2.5 non-overloaded pulse widths (measured using the InSight Virtual Oscilloscope).
Pulse Pile-Up Rejector Automatically set threshold. Pulse-pair resolution typically 500 ns.
Automatic Pole-Zero Computer-controlled. Can be set automatically or manually.
LLD Digital lower level discriminator set in channels. Hard cutoff of data in channels below
the LLD setting.
1
Ron Jenkins, R.W. Gould, and Dale Gedcke, Quantitative X-Ray Spectrometry (New York: Marcel Dekker,
Inc.), 1981, pp 266–267.
2
Note that this performance is superior to that of typical analog systems for which the specification is 70 ppm/C
(50 ppm for the amplifier in quadrature with 50 ppm for the ADC).
16
5. SPECIFICATIONS
Data Memory 16384 channels of non-volatile data memory; 2311 (2 billion) counts per
channel.
Presets Multiple presets may be set on any or all of the following:
Statistical Allows setting the required statistical accuracy on a key peak (for example, stop
counting when the activity of 60Co is known to be better than 5%).
Real/Live Time In multiples of 1 s.
Region of Interest Peak count.
Region of Interest Integral count adjustable to maximum value of 2321 counts (4 billion).
Data Overflow Terminates acquisition when data in any channel exceeds 2311 counts.
Digital Spectrum Stabilizer (controlled via the computer)
Stabilization Peak centroid (zero and gain) channel 2 to 16384; stabilization window width
(zero and gain) ±1 to ±256 channels.
Zero Correction Resolution ±64 channels with a minimum adjustment of 0.1 channel out
of 16384 total channels.
Gain Correction Resolution 0.00025% (from 99.5% to 100.5% in 4096 steps).
Bias Supply 0 to ±5000 V, continuously variable by potentiometer with an output current
between 0 and 100 µA; or ±1500 V, continuously variable by a potentiometer with an output
current between 0 and 500 µA. ON/OFF via computer control.
5.1.1. Indicators
High Voltage Front-panel LEDs for bias polarity, HV ON/OFF, and bias supply overload.
Processor BUSY Front-panel LED indicates microprocessor activity.
Stabilizer Front-panel, 7-segment LEDs indicate gain and offset values of the Stabilizer.
GAIN –999 to +999.
OFFSET –999 to +999.
17
DSPEC® Digital Gamma-Ray Spectrometer
Front-Panel LEDs
ACCEPT Green LED indicates an input has been processed.
REJECT Red LED indicates an input has been rejected.
DEADTIME 7-segment LED indicates system dead time, 0 to 99%.
POWER Front-panel LED indicates system power is ON.
5.1.2. Inputs and Outputs
INPUT Rear-panel BNC accepts preamplifier signals of either polarity, with rise times less
than the selected Flattop Time setting and exponential decay time constant in the range of 40 µs
to infinity (including transistor-reset and pulsed-optical reset preamplifiers). Input impedance
>500 , input is dc-coupled and protected to ±25 V.
ADC GATE Rear-panel BNC accepts slow positive NIM input; computer selectable as
coincidence or anti-coincidence. ADC GATE must overlap and precede the flattop region by
0.5 µs, and extend beyond the flattop region by 0.5 µs. The InSight Oscilloscope allows easy
alignment of the ADC GATE signal with the digital output pulse.
TRP INHIBIT Rear-panel BNC connector accepts reset signals from transistor-reset (TRP) or
pulsed-optical (OF) preamplifiers. Positive NIM logic or TTL level can be used. Inhibit input
initiates the protection against distortions caused by preamplifier reset. This includes turning off
the baseline restorer, monitoring the overload recovery, and generating the pile-up reject and
busy signals for the duration of the overload. These last two signals are used internally to
provide information to the dead-time correction circuitry.
HIGH VOLTAGE OUTPUT Rear-panel SHV connector, 0–5 kV (Zo = 2 M ). Computersensed.
REMOTE SHUTDOWN Rear-panel BNC is used to turn off the bias supply voltage in the
event that the detector warms up. This remote shutdown is compatible with any ORTEC
detector. The REMOTE SHUTDOWN must be connected to the Bias Shutdown of the detector,
or the high voltage will not turn on. For use with a detector with an incompatible shutdown
circuit, this feature can be defeated by placing a 100-, 50-, or 0- terminator on the REMOTE
SHUTDOWN input.
18
5. SPECIFICATIONS
NOTE THESE REMOTE SHUTDOWN PROPERTIES: An open circuit applied to
the REMOTE SHUTDOWN input indicates a warm detector; therefore, the high
voltage is turned off. Drawing a current of 500 µA from the REMOTE SHUTDOWN
input indicates a cool detector; therefore, the high voltage can be turned on.
The REMOTE SHUTDOWN input is clamped at 700 mV by an internal clamp.
CHANGE SAMPLE Rear-panel BNC provides TTL signal level to control an external device
such as a sample changer. CHANGE SAMPLE can be set for either TTL level via software
command.
SAMPLE READY Rear-panel BNC accepts TTL signal level from an external device such as
a sample changer. SAMPLE READY can be set to read either TTL level via software control.
PREAMP POWER Rear-panel, 9-pin D connector; provides ±24 V and ±12 V for
preamplifier power.
5.1.3. Controls
HIGH VOLTAGE BIAS 0–5 kV, rear-panel 10-turn precision potentiometer sets the value of
the bias voltage.
5.1.4. Interface Connectors
DUAL-PORT MEMORY Interface bus, rear-panel, 37-pin D connector.
RS-232-C Rear-panel standard RS-23-C, 9-pin D connector, male, wired as DTE to run at
19.2K baud maximum, with modem control.
ETHERNET Rear-panel BNC connector accepts IEEE 802.3 10BASE2 (thin coax).
5.2. Electrical and Mechanical
Dimensions 31 cm W × 35 cm D × 14 cm H (12–1/4 in. W × 13–3/4 in. D × 5–1/2 in. H).
Weight 7.7 kg (17 lbs).
Power Consumption 110 watts.
Operating Environment 0 to 50C.
19
DSPEC® Digital Gamma-Ray Spectrometer
5.3. Prerequisites
5.3.1. Hardware
A IBM®-compatible PC capable of running Microsoft® Windows® for Workgroups 3.11 is
required. Windows for Workgroups requires a 386 or higher processor, 8 megabytes (MB) of
RAM, and a 100-MB hard disk. At least 12 MB of RAM are recommended. For Ethernet, an
operating Windows for Workgroups network is required.
If running Windows 95 or Windows NT, the PC must have a 486 or higher processor, 12 MB of
RAM, and a 500-MB hard disk.
The software is supplied on 3.5-inch diskettes.
5.3.2. Software
Windows for Workgroups 3.11, Windows 95, or Windows NT.
20
6. COMMANDS AND RESPONSES
Communication with a DSPEC consists of sending command records to the MCB and receiving
response records from the MCB. Both command and response records consist of a sequence of
printable ASCII characters followed by an ASCII carriage return. The single exception to this
rule is the “#B” response record for the WRITE command, which contains binary integer
numbers. All commands eventually respond with a percent response record (so named because it
begins with an ASCII percent sign “%”) which signifies the completion of the command. SHOW
and STEP commands respond with a dollar response record (begins with an ASCII dollar sign
“$”) followed by a percent response record. The WRITE command can respond with multiple
pound sign records (begins with an ASCII pound sign “#”) but eventually completes by sending
a percent response record. All other commands result in a single percent response record upon
completion.
6.1. Command Records
Commands consist of a command header that may be followed by numeric parameter values.
The header consists of a verb or a verb and noun separated by an underscore; or a verb, noun,
and modifier, each separated by underscores. The verbs, nouns, and modifiers in the command
header are mnemonic words such as the verb ENABLE or the noun OVERFLOW that relate to
the function performed by the MCB when it executes the command. The first four letters of any
word will always be enough to uniquely identify the word when composing commands for an
MCB. For example, the command ENABLE_OVERFLOW_PRESET can be abbreviated to
ENAB_OVER_PRES.
Numeric parameters follow the command header separated by one or more spaces. Specific
commands require up to three parameters, separated by commas, which specify numeric
quantities related to the operation of the MCB, such as live time or conversion gain. The
command SET_WINDOW 0,16384 has two parameters, 0 and 16384, which set the window of
interest to start at channel 0 and continue for 16384 channels.
Some parameters listed in the command dictionary are considered optional and are distinguished
from mandatory parameters by being surrounded by brackets in the command prototype line
(e.g., SET_WINDOW [start,length]). Commands that have optional parameters may be sent to
the MCB without the optional parameters, in which case the behavior will be changed as
explained in the command description.
An optional checksum may be added to the end of any command sent to an MCB. The checksum
is a 1-byte unsigned integer sum of all of the characters in a command, treated as unsigned
integers, up to and including the comma or space(s) that separates the checksum from the
command. The checksum simply appears as an extra parameter added to the end of the command
parameter list. For commands that do not normally have parameters, the checksum appears as the
21
DSPEC® Digital Gamma-Ray Spectrometer
only parameter separated from the header by one or more spaces. All optional parameters must
be included in a command if a checksum.
is to be provided so that the checksum is not mistaken by the MCB as a parameter. For example,
the SET_WINDOW command must include the two optional parameters, start and length, if the
checksum is provided (e.g., SET_WINDOW 0,16384,209).
6.2. Percent Response Records
The MCB responds to all commands with a percent response record that signifies the completion
of the command. Percent response records contain two error code numbers and a 1-byte
checksum as follows:
%aaabbbccc<CR>
where % represents the ASCII % character, aaa represents the macro error code, bbb represents
the micro error code, ccc represents the checksum and <CR> represents the ASCII carriage
return character signifying the end of the record. The macro error code represents the general
class of error with 0 meaning no error, and the micro error code represents the sub-class of error
with 0 meaning no error. Following is a list of all percent responses for the DSPEC.
Unconditional Success:
%000000069<CR>
%000005074<CR>
%000006075<CR>
%000016076<CR>
%000032074<CR>
%000064079<CR>
No errors detected. Command executed as specified.
Device already started or stopped. The START or STOP command
was ignored.
Device preset already exceeded. The START command was
ignored.
START requested but amplifier not Pole-Zeroed since last powerup. START was attempted anyway.
START requested but High Voltage not enabled START was
attempted anyway.
Specified parameter was rounded to the closest legal value.
Note that the above responses can be combined to indicate a combination of warnings such
as:
Amplifier was not Pole-Zeroed nor was High Voltage enabled. The
%000048081<CR>
START was attempted anyway.
Device already started and High Voltage not enabled. The
%000037079<CR>
command was ignored.
Device already started, High Voltage not enabled and amplifier
%000053077<CR>
was not pole-zeroed. The command was ignored.
22
6. COMMANDS AND RESPONSES
%000038080<CR>
%000054078<CR>
Device preset already exceeded and High Voltage not enabled. The
command was ignored.
Device preset already exceeded, High Voltage not enabled and
amplifier was not pole-zeroed. The command was ignored.
Power-Up Alert:
%001000070<CR>
%003000072<CR>
Power-up just occurred and the selftest results are:
All power-up selftest passed.
Battery backed-up data lost.
Command Syntax Errors:
%129001082<CR>
%129002083<CR>
%129003084<CR>
%129004085<CR>
%129005086<CR>
%129006087<CR>
%129007088<CR>
%129132087<CR>
Invalid command verb.
Invalid command noun.
Invalid command verb and noun.
Invalid command modifier.
Invalid command verb and modifier.
Invalid command noun and modifier.
Invalid command verb, noun, and modifier.
Invalid command (verb, noun, and modifier valid but not together).
Communication Errors:
%130001074<CR>
%130002075<CR>
%130003076<CR>
%130004077<CR>
%130005078<CR>
%130006079<CR>
%130007080<CR>
%130008081<CR>
%130128084<CR>
%130129085<CR>
%130131078<CR>
%130132079<CR>
%130133080<CR>
Execution Errors:
%131128085<CR>
%131129086<CR>
%131130078<CR>
%131132080<CR>
%131134082<CR>
Serial line buffer overrun.
Serial line parity error.
Serial line buffer overrun and parity error.
Serial line framing error.
Serial line buffer overrun and framing error.
Serial line parity error and framing error.
Serial line buffer overrun, parity error, and framing error.
Serial line break detected.
Command checksum incorrect (only when optional checksum
provided).
Command (or WRITE handshake) record too long.
WRITE command aborted by “HA” handshake.
WRITE command aborted by timeout.
WRITE command aborted by invalid handshake.
Invalid 1st command parameter.
Invalid 2nd command parameter.
Invalid 3rd command parameter.
Invalid number of command parameters.
Invalid device or segment selected.
23
DSPEC® Digital Gamma-Ray Spectrometer
%131135083<CR>
%131136084<CR>
%131137085<CR>
Command not allowed while acquisition in progress.
Command not allowed in current mode of operation.
Hardware failure detected while processing command.
6.3. Dollar Response Records
SHOW and STEP commands respond with a single dollar response record followed immediately
by a percent response record. All valid dollar response records for each command are listed in
the command dictionary.
The following list provides the general form of each dollar response record for an MCB. In this
list, lower case letters represent numeric values. The letters “ccc” always represent an 8-bit
unsigned checksum of all characters on the record up to but not including the checksum
characters, and <CR> represents the ASCII carriage return character.
xxx is a single 8-bit unsigned number.
$Axxxccc<CR>
xxxxx is a single 16-bit unsigned number.
$Cxxxxxccc<CR>
xxxxx and yyyyy are 16-bit unsigned numbers.
$Dxxxxxyyyyyccc<CR>
xxxxx is a single 16-bit alarm mask.
$Exxxxxccc<CR>
ssss... is a variable length ASCII character sequence (no checksum
$Fssss...<CR>
is sent with this record).
xxxxxxxxxx is a single 32-bit unsigned number.
$Gxxxxxxxxxxccc<CR>
True response to a SHOW command (no checksum).
$IT<CR>
False response to a SHOW command (no checksum).
$IF<CR>
$Jxxxxxyyyyy...ccc<CR> Response to SHOW_CONFIGURATION command.
$Mxxxxxxxxxx...ccc<CR> Response to SHOW_STATUS command.
xxx, yyy, and zzz are 8-bit unsigned numbers.
$Nxxxyyyzzzccc<CR>
6.4. Command Catalog
This section lists each command with a description of its operation. The descriptions include a
list of any unusual responses that may result. As described in previous sections, the usual
response from a command is a %000000069<CR> response, which represents a macro error
code of 0 and a micro error code of 0 (no errors).
All execution error responses, if any, are listed for each command. Though syntax and
communication error responses may result from any command, in practice, these error responses
rarely occur on systems with reliable communication hardware running debugged software.
Refer to Section 6.2 for information about error responses.
24
6. COMMANDS AND RESPONSES
In the following catalog, the commands are listed in alphabetical order, each starting with a
command prototype line. Upper-case letters, numeric digits, blank spaces, and special symbols
such as the underscore ( _ ) and comma ( , ) in the prototype line are literal text to be sent to the
MCB exactly as they appear. Lower-case letters in the prototype line represent numeric values as
described in the accompanying text and should not be sent literally to the MCB but should be
replaced by an appropriate numeric value. Lower-case letters enclosed in quotes represent
alphanumeric character strings rather than numerical values. Items in the command prototype
that are surrounded by square brackets “[...]” are optional items and are not always required.
In this section the term <CR> represents the ASCII carriage return character, decimal value 13,
and the character “_” represents the ASCII underscore character, decimal value 95.
CLEAR
The channels of spectral data in the window of interest (see SET_WINDOW command) for
the currently selected device (see SET_DEVICE command) are set to zero. The live time and
true time counters for the currently selected device are also set to zero. This command is
equivalent to the combination of CLEAR_COUNTERS and CLEAR_DATA commands.
CLEAR_ALL
This command is equivalent to the combination of CLEAR_COUNTERS, CLEAR_DATA,
CLEAR_PRESETS, and CLEAR_ROI commands.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
CLEAR_COUNTERS
The live time and true time counters for the currently selected device (see SET_DEVICE
command) are set to zero.
CLEAR_DATA
The channels of spectral data in the window of interest (see SET_WINDOW command) for
the currently selected device (see SET_DEVICE command) are set to zero. The ROI flags are
not changed, nor are the presets changed.
CLEAR_PRESETS
The live time, true time, ROI integral, ROI peak, and overflow presets are all set to zero
(disabled) for the currently selected device (see SET_DEVICE command).
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
25
DSPEC® Digital Gamma-Ray Spectrometer
CLEAR_ROI
The region-of-interest flags for the channels in the window of interest (see SET_WINDOW
command) in the currently selected device (see SET_DEVICE command) are cleared.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
CLOSE_FILE “filename”
Completes download of file to RAM Disk in the MCB. See OPEN_FILE and WRITE_FILE.
This command may also be used to terminate a download to the FLASH without
reprogramming the FLASH.
CLOSE_FILE_FLASH crc
Completes download of FLASH data. Crc is the CRC checksum of the data which was
downloaded. See OPEN_FILE_FLASH and WRITE_FILE_FLASH.
Execution Errors:
Invalid number of command parameters.
%131132080<CR>
COMPUTER
Prepares the serial line for communication with a computer. In computer mode, text sent to
the DSPEC does not echo back to the host, and response records sent to the host by the
DSPEC are terminated only with a carriage return (no accompanying line feed). This
command has no effect when sent via the mailbox. See also TERMINAL.
DELETE_FILE “filename.ext”
Removes the specified file from the RAM Disk. This is not normally used.
Execution Errors:
Filename required.
%131128085<CR>
Hardware failure.
%131137085<CR>
DISABLE_ALARM
Ends the transmission of alarm responses when a device stops counting. Alarm responses are
disabled for the serial line and the mailbox communication paths independently. See also
ENABLE_ALARM and SHOW_ALARM.
DISABLE_BLRE_AUTOMATIC
Disables the automatic determination of baseline restorer time constant. See also
ENABLE_BLRE_AUTOMATIC, SET_BLRE, and SHOW_BLRE.
26
6. COMMANDS AND RESPONSES
DISABLE_GAIN_STABILIZATION
Stops stabilization of the gain peak while data is being acquired. The gain stabilization
adjustment is held at its current value until either gain stabilization is reenabled with the
ENABLE_GAIN_STABILIZATION command or reinitialized with the
INITIALIZE_GAIN_STABILIZATION, SET_GAIN_PEAK or SET_GAIN_WIDTH
command. See also SHOW_GAIN_STABILIZATION.
DISABLE_HV
Turns off the high-voltage output on the rear panel of the DSPEC. Note that with no external
load on the high-voltage output it takes approximately 60 seconds for the high voltage to
drop to zero volts. See the section on the bias supply for more information about the highvoltage output. See also ENABLE_HV and SHOW_HV.
DISABLE_OVERFLOW_PRESET
Disables the overflow preset for the currently selected device (see SET_DEVICE command).
Channels that receive a count when they contain 2147483647 counts, the maximum number
of counts, will roll over to zero counts if the overflow preset is disabled. See also
ENABLE_OVERFLOW_PRESET and SHOW_OVERFLOW_PRESET.
DISABLE_PZ_AUTOMATIC
Disables the automatic pole zero mode. See also ENABLE_PZ_AUTOMATIC.
DISABLE_REMOTE
Disables the recognition of commands on the alternate communication paths. If this
command is sent to the DSPEC via the mailbox communication path, it disables command
recognition on the serial path. If this command is sent via the serial path, it disables
command recognition on the mailbox communication path. See also ENABLE_REMOTE
and SHOW_REMOTE.
DISABLE_THRESHOLD_AUTOMATIC
Disables automatic positive and negative threshold determination. See
ENABLE_THRESHOLD_AUTOMATIC, SET_THRESHOLD_NEGATIVE, and
SET_THRESHOLD_POSITIVE.
DISABLE_THRESHOLD_SAMPLE
Allows InSight Oscilloscope to free-run without a trigger. See
ENABLE_THRESHOLD_SAMPLE and SET_THRESHOLD_SAMPLE.
DISABLE_ZERO_STABILIZATION
Stops stabilization of the zero peak while data is being acquired. The zero stabilization
adjustment is held at its current value until either zero stabilization is reenabled with the
27
DSPEC® Digital Gamma-Ray Spectrometer
ENABLE_ZERO_STABILIZATION command or reinitialized with the
INITIALIZE_ZERO_STABILIZATION, SET_ZERO_CHANNEL or SET_ZERO_WIDTH
commands. See also SHOW_ZERO_STABILIZATION.
ENABLE_ALARM
Begins the transmission of alarm responses, $E records, when an input stops counting. A $E
response record will be transmitted only when no host commands are being processed (after
a % response from a previous command and before another command is sent). Alarm
responses are enabled for the serial line and the mailbox communication paths
independently. If the command is sent to the MCB via the mailbox, then alarms will be sent
to the mailbox. If the command is sent via the serial line, then alarms will be sent via the
serial line. Alarms can be enabled for both communication paths at the same time. See also
DISABLE_ALARM and SHOW_ALARM.
ENABLE_BLRE_AUTOMATIC
Enables the automatic determination of baseline restorer time constant. See also
DISABLE_BLRE_AUTO, SHOW_BLRE, and SET_BLRE.
ENABLE_GAIN_STABILIZATION
Enables the stabilization of the gain peak by the previously selected method, either Gauss
mode or point mode (see SET_MODE_GAUSS and SET_MODE_POINT). Spectrum
stabilization is available only on device 1. See also DISABLE_GAIN_STABILIZATION,
SHOW_GAIN_STABILIZATION, and INITIALIZE_GAIN_STABILIZATION.
ENABLE_HV
Turns on the high-voltage output on the rear panel of the DSPEC. The voltage selected on
the rear panel will be present on the high-voltage output within 60 seconds after this
command is received unless the output is overloaded or the output is shut down by the highvoltage shutdown. See also DISABLE_HV and SHOW_HV.
Execution Errors:
The high voltage could not be enabled due to a high voltage
%131137085<CR>
shutdown condition.
ENABLE_OVERFLOW_PRESET
Enables the overflow preset for the currently selected device (see SET_DEVICE command).
Channels that receive a count when they contain 2147483647 counts, the maximum number
of counts, will stop the acquisition for that channel’s device if the overflow preset is enabled.
The channel that caused the preset to complete will contain 2147483647 counts. An alarm
response record will be sent to the host if alarms are enabled for the device whose acquisition
is stopped (see ENABLE_ALARM command). See also DISABLE_OVERFLOW_PRESET
and SHOW_OVERFLOW_PRESET commands.
28
6. COMMANDS AND RESPONSES
ENABLE_PZ_AUTOMATIC
Enables the automatic pole zero mode. See also DISABLE_PZ_AUTO and
SHOW_PZ_AUTO.
ENABLE_REMOTE
Enables the recognition of commands on the alternate communication path. If this command
is sent to the DSPEC via the mailbox it enables command recognition on the serial line. If
this command is sent via the serial line it enables command recognition in the mailbox.
ENABLE_THRESHOLD_AUTOMATIC
Enables automatic determination of the positive and negative thresholds. See also
DISABLE_THRESHOLD_AUTO, SHOW_THRESHOLD_AUTO,
SET_THRESHOLD_NEGATIVE, and SET_THRESHOLD_POSITIVE.
ENABLE_THRESHOLD_SAMPLE
Enables the trigger threshold in InSight mode. See also
DISABLE_THRESHOLD_SAMPLE, SET_THRESHOLD_SAMPLE, and
SHOW_THRESHOLD_SAMPLE.
ENABLE_ZERO_STABILIZATION
Enables the stabilization of the zero peak by the previously selected method, either Gauss
mode or point mode (see SET_MODE_GAUSS and SET_MODE_POINT). See also
DISABLE_ZERO_STABILIZATION, SHOW_ZERO_STABILIZATION, and
INITIALIZE_ZERO_STABILIZATION.
INITIALIZE_GAIN_STABILIZATION
Resets the gain peak stabilization adjustment to unity (no adjustment). This value is reported
as 2048 by the SHOW_GAIN_ADJUSTMENT command. See also
SET_GAIN_ADJUSTMENT, ENABLE_GAIN_STABILIZATION, and
DISABLE_GAIN_STABILIZATION.
INITIALIZE_ZERO_STABILIZATION
Resets the zero peak stabilization adjustment to unity (no adjustment). This value is reported
as 2048 by the SHOW_ZERO_ADJUSTMENT command. See also
SET_ZERO_ADJUSTMENT, ENABLE_ZERO_STABILIZATION, and
DISABLE_ZERO_STABILIZATION.
OPEN_FILE “filename.ext”
A filename is needed to open a file. Begins the download of a file to the RAM Disk by
opening filename.ext on the RAM Disk. See WRITE_FILE and CLOSE_FILE.
29
DSPEC® Digital Gamma-Ray Spectrometer
OPEN_FILE_FLASH
Begins the download of a new FLASH (ROM DISK). This command removes all files on the
RAM Disk except autoexec.bat and ini83905.exe to make room for ROMDISK.ABS. It
also stops all acquisitions which are in progress. See WRITE_FILE_FLASH and
CLOSE_FILE_FLASH.
PAUSE_INPUT [input-num]
Waits for the next transition on the Sample Ready input or the beginning of the next
command before responding with a % response record. If input-num is present, it must be 0.
This parameter is provided for compatibility with other ORTEC modules.
Responses:
Transition on Sample Ready input occurred.
%000000069<CR>
Command was aborted by beginning of next command.
%130131041<CR>
PAUSE_INPUT_HIGH [input-num]
Waits for a high level to be detected on the Sample Ready input or for the beginning of the
next command before responding with a % response record. The input level must remain
high until the MCB responds; otherwise, it may not be detected. If input-num is provided, it
must be zero. This parameter is provided for compatibility with other ORTEC modules.
Responses:
High level was detected on the input.
%000000069<CR>
Command was aborted by beginning of next command.
%130131041<CR>
PAUSE_INPUT_LOW [input-num]
Waits for a low level to be detected on the Sample Ready input or for the beginning of the
next command before responding with a % response record. The input level must remain low
until the MCB responds; otherwise, it may not be detected. If input-num is provided, it must
be zero. This parameter is provided for compatibility with other ORTEC modules.
Responses:
Low level was detected on the input.
%000000069<CR>
Command was aborted by beginning of next command.
%130131041<CR>
REBOOT
Reboots the MCB. This command is not normally used and may terminate communication.
MCB returns a 000130.
RESET
Resets the DSPEC to the state just after power is applied. This command responds with a %
response that indicates power-up just occurred.
30
6. COMMANDS AND RESPONSES
RESET_DSP value
Resets all or part of the digital signal processor. A value of 0 resets the entire processor, 1
resets the programmable logic only, and 2 resets the digital signal processor (DSP) chips.
This command is only used for test purposes.
RESET_REMOTE
Resets any UART error conditions when sent to the DSPEC via the mailbox. Resets mailbox
communications when sent to the DSPEC via the serial communications path.
SAMPLE
Sending this command causes another waveform to be captured in InSight mode. This
command is invalid when not in InSight mode.
Execution Errors:
Command not allowed in current mode of operation.
%131136084<CR>
SET_ADC_HOLDOFF holdoff
Prevents data acquisition from monopolizing the microprocessor, so the microprocessor can
perform other tasks such as communication with the host computer. Holdoff can be from
0–65535. This command is not normally used. See also SHOW_ADC_HOLDOFF.
SET_BLRE baseline
This sets the baseline restorer time constant to the value baseline. Baseline is in
microseconds with a range from 10–100. The specified value is only used if automatic
baseline restorer mode is disabled. See also ENABLE_BLRE, DISABLE_BLRE, and
SHOW_BLRE.
Execution Warnings:
Value was rounded to the closest legal value.
%000064079<CR>
SET_CONFIGURATION_UART “bbbbbpds”
A syntax error. See also SHOW_CONFIGURATION_UART. Sets the baud rate, parity,
number of data bits and the number of stop bits for serial port communication. The parameter
is an ASCII string which specifies the settings where bbbbb is the baud rate with leading
zeros if necessary, p is replaced with O, E, or N to indicate odd, even, or no parity, d is
replaced with the number of data bits (5–8), and s is replaced with the number of stop bits
(1–2). For example SET_CONFIG_UART “09600N81” sets the baud rate to 9600, disables
parity checking, sets the number of bits to 8 and the number of stop bits to 1.
SET_CORRECTION_FLAT flat
This sets the flattop correction to flat. The flattop correction is normally determined with the
OPTIMIZE command. See also SHOW_CORRECTION_FLAT.
31
DSPEC® Digital Gamma-Ray Spectrometer
SET_DATA [start, chans],value
If the optional start and chans parameters are included in this command, the range of
channels specified by start and chans is loaded with value. Sets all channels of spectral data
in the window of interest (see SET_WINDOW command) for the currently selected device
(see SET_DEVICE command) to the specified count. ROI flags are not affected.
SET_DATE day,month,year
Sets the date stored in the battery backed-up system clock to the specified values. Day can be
any value from 1–31; month any value from 1–12; and year any value from 0–99. The
current date and time are stored for a device when an acquisition is started. See also
SHOW_DATE, SET_TIME, and SHOW_TIME.
SET_DATE_START day,month,year
Sets the start date for the currently selected device (see SET_DEVICE command) to the
specified values. Normally the start date and time are set automatically whenever a device is
started with the START command. See also SHOW_DATE_START, SET_TIME_START,
and SHOW_TIME_START.
SET_DCREST value
This controls the speed of the analog DC restorer. The smaller the value, which must be
between 0 and 4095, the slower the DC restorer operates. The default setting, 2000, is
normally sufficient. See also SHOW_DCREST.
SET_DEBUG level
Sets the debug level to level, which must be between 0 and 255. Setting level to a non-zero
value causes debugging information to be transmitted to the serial port. See also
SHOW_DEBUG.
SET_DELAY_COLLECTION value
Controls the pile-up rejector by setting a width threshold such that if a fast channel
discriminator pulse is wider than value, the pulse is rejected. This portion of the pile-up
rejector rejects pulses that are too close together to be detected separately by the fast channel.
Value is in microseconds with a range from 0.250–1.6 in steps of 0.05. See also
SHOW_DELAY_COLLECTION.
SET_DELAY_SAMPLE num
Delays the waveform collected in InSight mode by num points. Num must be between 0 and
65535. See also SHOW_DELAY_SAMPLE.
32
6. COMMANDS AND RESPONSES
SET_DEVICE device
This command is provided for compatibility with the Model 919. Only device number 1 is
valid for a DSPEC.
SET_DSP num, command,value
This is a debugging command that can be used to directly modify parameters within the
digital signal processor chips. Num (1–4) selects the DSP chip that will receive the
command; command (0–7) indicates which parameter will be changed; and value (–8388608
to 8388607 or –1.0 to 1.0) specifies the new value as either a 24-bit signed integer or a
floating point value. See also SHOW_DSP.
Execution Errors:
There are three parameters.
%131132080<CR>
The first parameter is incorrect.
%131128085<CR>
The second parameter is incorrect.
%131129086<CR>
The third parameter is incorrect.
%131130078<CR>
SET_GAIN_ADJUSTMENT value
Sets the gain stabilization adjustment to an arbitrary value from –65535 to 65535. This
adjustment is usually made only by the gain stabilizer, and reset to 0 with the
INITIALIZE_GAIN_STABILIZATION command. See also
SHOW_GAIN_ADJUSTMENT.
Execution Errors:
The command was attempted when the currently selected device
%131134082<CR>
was other than device 1.
SET_GAIN_CHANNEL chan
Sets the center channel for the stabilizer gain peak. If a gain channel is chosen such that the
beginning channel or ending channel would be below channel 0 or above the maximum
channel as determined by the conversion gain, the gain peak width is reduced until the peak
fits the device boundaries. A gain channel and width must be set before gain stabilization can
be enabled.
Execution Errors:
The specified channel number would create a peak that was less
%131128085<CR>
than the minimum width (3 channels) or would be outside the
device’s range.
The command was attempted while gain stabilization was enabled.
%131136084<CR>
SET_GAIN_COARSE num
This sets the coarse gain to num, which must be one of the following: 1, 2, 5, 10, 20, 50,
100. See also SHOW_GAIN_COARSE.
33
DSPEC® Digital Gamma-Ray Spectrometer
SET_GAIN_CONVERSION chans
Sets the conversion gain. The conversion gain defines the number of channels within the
device that will used for spectral data. This has the effect of altering the resolution of the
ADC from 14 bits (conversion gain = 16384) to 9 bits (conversion gain = 512) for the device.
See also SHOW_GAIN_CONVERSION.
Legal Commands:
Conv. gain set to default (16384).
SET_GAIN_CONVERSION 0<CR>
Conv. gain set to 512 channels.
SET_GAIN_CONVERSION 512<CR>
Conv. gain set to 1024 channels.
SET_GAIN_CONVERSION 1024<CR>
Conv. gain set to 2048 channels.
SET_GAIN_CONVERSION 2048<CR>
Conv. gain set to 4096 channels.
SET_GAIN_CONVERSION 4096<CR>
Conv. gain set to 8192 channels.
SET_GAIN_CONVERSION 8192<CR>
SET_GAIN_CONVERSION 16384<CR> Conv. gain set to 16384 channels.
SET_GAIN_FINE value
This sets the fine gain to value. Value is a floating point value from 0–0.999995. See also
SHOW_GAIN_FINE.
SET_GAIN_PRESET count
Sets the Gauss mode stabilization preset for the gain peak. The preset represents the
minimum number of incremental counts that must be collected in any one channel of the gain
peak before the gain is evaluated by the stabilizer and potentially adjusted. See also
SHOW_GAIN_PRESET.
SET_GAIN_WIDTH chans
Sets the width in channels for the stabilizer gain peak. The gain width must be chosen such
that the beginning channel is no lower than channel 0 and the ending channel is no higher
than the maximum channel as determined by the conversion gain. The gain channel and
width must be set before gain stabilization can be enabled. The absolute minimum width for
the gain peak is 3 channels, and the absolute maximum width for the gain peak is 256
channels in Gauss mode. In point mode there is no maximum peak width, though the chosen
width must allow the peak to fit within the device’s channel limits as stated above. See also
SHOW_GAIN_WIDTH, SET_GAIN_CHANNEL and SHOW_GAIN_CHANNEL.
Execution Errors:
The specified number of channels would create a peak that was less
%131128085<CR>
than the minimum (3 channel) width or would be outside the
device’s range.
The command was attempted while gain stabilization was enabled.
%131136084<CR>
34
6. COMMANDS AND RESPONSES
SET_GATE_ANTICOINCIDENT
Causes the DSPEC to expect the ADC gate input signal in anticoincident mode. See also
SET_GATE_OFF, SET_GATE_COINCIDENT, and SHOW_GATE.
SET_GATE_COINCIDENT
Causes the DSPEC to expect the ADC gate input signal in coincident mode. See also
SET_GATE_OFF, SET_GATE_ANTICOINCIDENT, and SHOW_GATE.
SET_GATE_OFF
Causes the DSPEC to ignore the state of the ADC gate input signal. See the section on the
ADC gate input for more information. See also SET_GATE_COINCIDENT,
SET_GATE_ANTICOINCIDENT, and SHOW_GATE.
SET_GATE_SYNC
Debugging command that causes the gate input to become a trigger output in InSight mode.
SET_INTEGRAL_PRESET count
Sets the ROI integral preset to the specified count. During data acquisition when the sum of
the counts contained in the channels that have the ROI flag set reaches the integral preset
count, the preset is complete and the acquisition is stopped. The actual number of counts in
the ROI integral may exceed the preset value by up to 512 counts due to the pipelined
architecture of the DSPEC. Setting an integral preset to 0 counts disables the preset. The
integral preset may be set to from 0 (disabled) to 4294967295 counts. See also
CLEAR_PRESETS and SHOW_INTEGRAL_PRESET.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
SET_LIVE ticks
Sets the live-time counter to the specified number of ticks. The number represents live time
in units of 20 milliseconds (50 ticks per second). Normally this value is set by the DSPEC
during data acquisition. See also CLEAR_COUNTERS and SHOW_LIVE.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
SET_LIVE_PRESET ticks
Sets the live-time preset to the specified number of ticks. During data acquisition when the
live-time counter reaches the preset number of ticks, the preset is complete and the
acquisition is stopped. Setting a live-time preset to 0 ticks disables the preset. See also
CLEAR_PRESETS and SHOW_LIVE_PRESET.
35
DSPEC® Digital Gamma-Ray Spectrometer
Execution Errors:
%131135083<CR>
The command was attempted while spectrum acquisition was in
progress. No action was taken.
SET_LLD chan
Sets the lower level discriminator to chan, which must be between 0 and 16383. See also
SHOW_LLD.
SET_LOCATION_SAMPLE num
Sets which location in the digital filter will be displayed in InSight mode. Normally, num is
set to 3 to sample the output of the digital filter. Setting num to 0–2 samples intermediate
points in the filter for debugging purposes. See also SHOW_LOCATION_SAMPLE.
SET_MODE_GAUSS
Sets the method of stabilization for both gain and zero stabilization peaks to Gauss mode.
The maximum peak width is 256 channels in Gauss mode, so that either the gain or zero (or
both) peak(s) may be reduced in width. See also SET_MODE_POINT.
SET_MODE_PHA
The mode is set to PHA.
SET_MODE_POINT
Sets the method of stabilization for both gain and zero stabilization peaks to point mode. See
also SET_MODE_GAUSS.
SET_MODE_TEST value
Sets the test mode to value. Value = 0 exits test mode, 1 is ADC test mode, and 2 is DSP test
mode.
SET_MODE_SAMPLE
Starts InSight Oscilloscope mode.
SET_NETWORK_ID id
Establishes a new network identifier which is to be used by the MCB for ethernet
communication. The setting only takes effect after a REBOOT. id should be no more than 15
characters. See also SHOW_NETWORK_ID.
SET_NETWORK_ADDRESS [company,]addr
Establishes the Ethernet address used by the 83905 Ethernet chip. The company portion of
the address is usually not included causing the ORTEC ID (41020) to be used. The addr
portion should not be the same on any two MCBs connected to the network. This address is
36
6. COMMANDS AND RESPONSES
assigned at the factory and should normally never be changed. See also SHOW_
NETWORK_ADDRESS.
Execution Errors:
The number must be between 0 and 16777215.
%131128085<CR>
SET_OUTPUT port, value
This sends the value to the port. The port number can be 0 or 1; 0 is the change sample
output and 1 is the serial port. Value must be between 0 and 255. See also SHOW_OUTPUT.
SET_OUTPUT_HIGH [output-num]
Sets the Change Sample output to a high level. If output-num is provided, it must be zero.
This parameter is provided for compatibility with other ORTEC modules.
SET_OUTPUT_LOW [output-num]
Sets the Change Sample output to a low level. If output-num is provided, it must be zero.
This parameter is provided for compatibility with other ORTEC modules.
SET_PAGE num
Debugging command that maps the DPM to page num; num can range from 1–4. See also
SHOW_PAGE.
SET_PEAK_DELAY value
Sets the peak detect delay parameter to value. Value can range from 0–7; it is normally set
to 2. See also SHOW_PEAK_DELAY.
SET_PEAK_LENGTH value
Sets the peak detect length parameter to value. Value can range from 0–7; it is normally set
to 3. See also SHOW_PEAK_LENGTH.
SET_PEAK_PRESET count
Sets the ROI peak preset to the specified count. During data acquisition when the contents of
any channel of a device that has the ROI flag set reaches the peak preset count, the preset is
complete and the acquisition is stopped. The actual number of counts in the ROI peak may
exceed the preset value by a small number of counts due to the pipelined architecture of the
DSPEC. Setting a peak preset to 0 counts disables the preset. The peak preset may be set to
from 0 (disabled) to 2147483647 counts. See also CLEAR_PRESETS and
SHOW_PEAK_PRESET.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
37
DSPEC® Digital Gamma-Ray Spectrometer
SET_PZ num
This sets the pole zero to num, which must be between 0 and 4095. See also ENABLE
_PZ_AUTO, SHOW_PZ, and DISABLE_PZ_AUTO.
SET_PZ_DELAY num
Sets the time in 400-ns to wait after the peak of a pulse before sampling the baseline to
evaluate the quality of the PZ adjustment when automatic pole-zero adjustment is in
progress. Num should be between 0 and 200. Normally, the parameter is selected
automatically by the DSPEC, based on the rise time setting. See also SHOW_PZ_DELAY.
Execution Errors:
The number is incorrect.
%131128085<CR>
A number must be included.
%131132080<CR>
SET_RADIX_BINARY
This command is provided for compatibility with other ORTEC MCBs. It specifies that
binary records are to be used by the WRITE command for sending spectral data to the host
computer via the serial line. This is the only radix supported by the DSPEC.
SET_ROI start_chan,number_of_chans
Sets the ROI flags for the specified channels. This command can be used multiple times to
set ROI flags without affecting previously set flags. ROI flags specify channels within a
device that are considered for ROI integral and ROI peak presets.
SET_ROI_SAMPLE num
Selects which controls signals are displayed as an ROI on the captured waveform. The
selected signals are logically anded and if the result is not zero, the ROI bit is turned on. The
following signals may be selected with the associated bit.
Pile-up Reject
Bit 0:
Negative Baseline Threshold
Bit 1:
Baseline Restorer Gate
Bit 2:
Positive Baseline Threshold
Bit 3:
Busy
Bit 4:
Gate
Bit 5:
Reserved
Bit 6:
Peak Detect
Bit 7:
Reserved
Bit 8:
SET_ROI_UNCERTAINTY start, chans
Sets the region to be used for the uncertainty preset calculation. See also
SHOW_ROI_UNCERTAINTY.
38
6. COMMANDS AND RESPONSES
SET_SEGMENT number
Provided for compatibility with Model 918-type MCBs. This command has no effect for the
DSPEC. The segment number may be any value from 1 through 16.
Execution Errors:
The specified segment number was either zero or a value greater
%131128085<CR>
than 16.
SET_SHAP_CUSP value
Sets the cusp factor to value. Valid values are 0.2–1.0. See also SHOW_SHAP_CUSP.
SET_SHAP_FLAT value
Sets the width of the flattop to value. Value is in microseconds, ranging from 0.8–2.0 in steps
of 0.4. See also SHOW_SHAP_FLAT.
SET_SHAP_RISE value
Sets the risetime to value. Value is in microseconds, ranging from 0.8–25.6 in steps of 0.8.
See also SHOW_SHAP_RISE.
SET_SNUM “serialnumber”
Stores the serial number of the unit in non-volatile memory inside the MCB. The serial
number must be 8 characters or less. See also SHOW_SNUM.
SET_THRESHOLD_NEGATIVE value
Sets the negative threshold to value. The negative threshold is normally set automatically by
the DSPEC. See also ENABLE_THRESHOLD_AUTOMATIC and
SHOW_THRESHOLD_NEGATIVE.
SET_THRESHOLD_POSITIVE value
Sets the positive threshold to value. The positive threshold is normally set automatically by
the DSPEC. See also ENABLE_THRESHOLD_AUTOMATIC and
SHOW_THRESHOLD_POSITIVE.
SET_THRESHOLD_SAMPLE value
Sets the sample threshold to value. In InSight mode the sample threshold is used as the trigger
level. See also SHOW_THRESHOLD_SAMPLE.
SET_TIME hour,min,sec
Sets the time stored in the battery backed-up system clock to the specified values. hour can be
any value from 0–23; min and sec can be any value from 0–59. The current date and time are
stored for a device when an acquisition is started. See also SHOW_TIME, SET_DATE,
SHOW_DATE, SET_TIME_START, and SHOW_TIME_START.
39
DSPEC® Digital Gamma-Ray Spectrometer
Execution Errors:
%131137085<CR>
The time could not be set due to a hardware malfunction. Hardware
service may be required.
SET_TIME_START hour,min,sec
Sets the start time to the specified values. Normally the start date and time are set
automatically whenever a device is started with the START command. See also
SHOW_TIME_START, SET_DATE_START, SHOW_DATE_START, SET_DATE, and
SET_TIME.
SET_TRUE ticks
Sets the true-time counter to the specified number of ticks. The number represents true time
in units of 20 milliseconds (50 ticks per second). Normally this value is set by the DSPEC
during data acquisition. See also CLEAR_COUNTERS and SHOW_TRUE.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
SET_TRUE_PRESET ticks
Sets the true-time preset to the specified number of ticks. During data acquisition when the
true-time counter reaches the preset number of ticks, the preset is complete and the
acquisition is stopped. Setting a true-time preset to 0 ticks disables the preset. See also
CLEAR_PRESETS and SHOW_TRUE_PRESET.
Execution Errors:
The command was attempted while spectrum acquisition was in
%131135083<CR>
progress. No action was taken.
SET_UNCERTAINTY_PRESET percent
Sets the uncertainty preset to the specified value in percent. percent is a floating point value
from 0–99.9999. See also SHOW_UNCERTAINTY_PRESET.
Execution Errors
The value is incorrect.
%131128085<CR>
A value must be included.
%131132080<CR>
SET_WIDTH bytes
Sets the maximum number of bytes that may be sent to the host computer by the WRITE
command.
40
6. COMMANDS AND RESPONSES
Legal Commands:
SET_WIDTH 0<CR>
SET_WIDTH 12<CR>
...
SET_WIDTH 512<CR>
Width set to default (512).
Width set to minimum value of 12 bytes.
...
Width set to maximum value of 512 bytes.
SET_WINDOW [start, length]
Sets the window of interest to the specified start channel and number of channels. The
channels of spectral data in the window of interest are affected by commands such as LEAR,
SET_DATA, and WRITE. If neither start nor length is provided, the window is set to the
maximum size allowed by the conversion gain specified. The window of interest is always set
to the maximum size after a SET_DEVICE command or a SET_SEGMENT command.
Execution Errors:
The start channel was higher than the conversion gain.
%131128085<CR>
The length specified one or more channels that were too high
%131129086<CR>
conversion gain.
The start channel was specified without a length. If one value
%131132080<CR>
is given, the other must also be given.
SET_ZERO_ADJUSTMENT value
Sets the zero stabilization adjustment to an arbitrary value from –65535 to 65535. The total
range of the adjustment value represents ±256 channels. This adjustment is usually only
made by the gain stabilizer, and reset to 0 with the INITIALIZE_ZERO_STABILIZATION
command. See also SHOW_ZERO_ADJUSTMENT.
SET_ZERO_CHANNEL chan
Sets the center channel for the stabilizer zero peak. If a zero channel is chosen such that the
beginning channel or ending channel would be below channel 0 or above the maximum
channel, as determined by the conversion gain, the zero peak width is reduced until the peak
fits the device boundaries. A zero channel and width must be set before zero stabilization can
be enabled. See also ENABLE_ZERO_STABILIZATION.
Execution Errors:
The specified channel number would create a peak that was
%131128085<CR>
less than the minimum width (3 channels) or would be
outside the device’s range.
The command was attempted while zero stabilization was
%131136084<CR>
enabled.
SET_ZERO_PRESET count
Sets the Gauss mode stabilization preset for the zero peak. The preset represents the minimum
number of incremental counts that must be collected in any one channel of the zero peak
41
DSPEC® Digital Gamma-Ray Spectrometer
before the zero offset is evaluated by the stabilizer and potentially adjusted. See also
SHOW_ZERO_PRESET.
SET_ZERO_WIDTH chans
Sets the width in channels for the stabilizer zero peak. The zero width must be chosen such
that the beginning channel is no lower than channel 0 and the ending channel is no higher
than the maximum channel as determined by the conversion gain. The zero channel and width
must be set before zero stabilization can be enabled. The absolute minimum width for the
zero peak is 3 channels, and the absolute maximum width for the zero peak is 256 channels in
Gauss mode. In point mode there is no maximum peak width, though the chosen width must
allow the peak to fit within the device’s channel limits as stated above.
Execution Errors:
The specified number of channels would create a peak that was less
%131128085<CR>
than the minimum width (3 channels) or would be outside the
devices range.
The command was attempted while zero stabilization was enabled.
%131136084<CR>
SHOW_ACTIVE
Returns a 1 if the DSPEC is active (i.e., acquiring spectral data) or 0 if it is not active.
Responses:
Not active.
$C00000087<CR>
Active.
$C00001088<CR>
SHOW_ACTIVE_DEVICES
Returns a bit mask of the currently active devices as follows:
Responses:
No devices are active.
$C00000087<CR>
Only device 1 is active.
$C00001088<CR>
SHOW_ADC_CONVERSION
Debugging command that returns the most recent conversion from the ADC. Returns 0 if no
conversion is available. See also SET_ADC_CONVERSION command.
Responses:
No conversion available.
$C00000087<CR>
405 was the most recent conversion.
$C00405096<CR>
SHOW_ALARM
Returns a record showing whether the alarm responses are enabled or disabled for a particular
communication path. If SHOW_ALARM is received on the serial line, the response indicates
whether alarms are enabled for the serial line. If SHOW_ALARM is received by the mailbox,
the response indicates whether alarms are enabled for the mailbox.
42
6. COMMANDS AND RESPONSES
Responses:
$IT<CR>
$IF<CR>
Alarms are enabled for the specified communication path.
Alarms are disabled for the specified communication path.
SHOW_BLRE
Shows the baseline restorer time constant in microseconds. See also SET_BLRE.
Responses:
Time constant is 91 µs.
BLUE 000000000000091
SHOW_BLRE_AUTOMATIC
Shows whether automatic selection of the baseline restorer constant is off or on.
Responses:
Automatic baseline is enabled.
$IT<CR>
Automatic baseline is disabled.
$IF<CR>
SHOW_CONFIGURATION
Returns a record that indicates the hardware configuration of the MCB. The record contains
information about the number of segments in an MCB device (always 1 for the DSPEC), and
the current conversion gain for each segment. The record is organized as follows:
$J1638400001aaaaa00000[65 zeros here for total of 75 zeros]00000ccc
where aaaaa represents the conversion gain for the one and only segment in the currently
selected device, and ccc represents the record checksum. See the section on response records
in this chapter for more information about response records and checksums.
SHOW_CONFIGURATION_UART
Reports the baud rate, parity option, number of data bits, and number of stop bits for the serial
interface.
Responses:
9600 baud, no parity, 8 data bits, 1 stop bit.
$F09600N81
19200 baud, even parity, 8 data bits, 2 stop bits.
$F19200E82
2400 baud, odd parity, 7 data bits, 1 stop bits.
$F02400O71
SHOW_CORRECTION_FLAT
Shows the flattop correction value. See also SET_CORR_FLAT.
Responses:
CORR_FLAT 000000000000000
SHOW_DATE
Returns the day, month, and year of the current date as maintained in the battery-backed-up
real time clock, in the form dddmmmyyy. The day is returned as a 3-digit integer number
43
DSPEC® Digital Gamma-Ray Spectrometer
from 001–031, month as a 3-digit integer number from 001–012, and year as a 3-digit integer
number from 000–099. See also SET_DATE_START.
Responses:
Date reported as Jan 1, 1988.
$N001001088052<CR>
...
...
Date reported as Dec 31, 1999.
$N031012099059<CR>
Date reported as Jan 1, 2000.
$N001001000036<CR>
...
...
Date reported as Dec 31, 2087.
$N031012087056<CR>
SHOW_DATE_START
Returns the day, month and year of the acquisition start date in the form dddmmmyyy. The
day is returned as a 3-digit integer number from 001–031, month as a 3-digit integer number
from 001–012, and year as a 3-digit integer number from 000–099. See also
SET_DATE_START.
Responses:
Date reported as Jan 1, 1988.
$N001001088052<CR>
...
...
Date reported as Dec 31, 1999.
$N031012099059<CR>
Date reported as Jan 1, 2000.
$N001001000036<CR>
...
...
Date reported as Dec 31, 2087.
$N031012087056<CR>
SHOW_DCREST
Shows the DC restorer setting. See also SET_DCREST.
Responses:
DCRE002000
SHOW_DEBUG
Shows the debug level. See also SET_DEBUG.
Responses:
Returns the Debug state as $Axxxccc, where xxx is the
$A003248
Debug level and ccc is the checksum.
SHOW_DELAY_COLLECTION
Shows the Delay Collection setting. See also SET_DELAY_COLLECTION.
Responses:
DEL_COLL 0000000000001.6
44
6. COMMANDS AND RESPONSES
SHOW_DELAY_SAMPLE
Shows the Delay Sample setting. See also SET_DELAY_SAMPLE.
Responses:
The sample number is 00003, and 090 is the checksum.
$C00003090
SHOW_DEVICE
Returns the number of the currently selected device (see SET_DEVICE command). See also
START and STOP.
Responses:
Device number 1 is currently selected device.
$A001246<CR>
Device number 2 is currently selected device.
$A002247<CR>
Device number 3 is currently selected device.
$A003248<CR>
Device number 4 is currently selected device.
$A004249<CR>
SHOW_DIRECT [“filename.ext”]
Responds with the first item in the RAM Disk or ROM Disk directory which matches the
specified file name. Wildcards are permissible and if a drive letter is included, A: should be
used for the ROM Disk and C: should be used for the RAM Disk. If no drive letter is
included, C: is used. If no filename is included, C:*.* is used. SHOW_DIRECTORY_NEXT
returns the next entry in the directory list.
Responses:
MCBLOCAL.INI 97 01-10-1997 04:24
SHOW_DIRECT_ALL [“filename.ext”]
Responds with the directory entries on the RAM Disk or ROM Disk directory which match
the specified filename. Wildcards are permissible and if a drive letter is included, A: should
be used for the ROM Disk and C: should be used for the RAM Disk. If no drive letter is
included, C: is used. If no filename is included, C:*.* is used. This command returns multiple
response records until all matching directory entries have been returned.
Responses:
MCBLOCAL.INI 97 01-10-1997 04:24
SHOW_DIRECT_NEXT
Responds with the next matching directory entry which matches the filename specified in a
SHOW_DIRECTORY command. If there are no more matching entries, a %131137 response
is returned.
Execution Errors:
No more matching entries.
%131137085<CR>
45
DSPEC® Digital Gamma-Ray Spectrometer
SHOW_DITHER
Show the status of the dither.
Responses:
DITH_ENA 000000
DITH_DIS 000000
Dither is enabled.
Dither is disabled.
SHOW_DSP num, command
Debugging command that can be used to directly read parameters within the digital signal
processor chips. Num (1–4) selects which DSP chip will receive the command and command
(0–7) indicates which parameter will be reported. The command responds with both a 24-bit
signed representation and a floating point representation of the parameter.
Responses:
Parameter is set to 0.5.
DSP 000000004194304 0000000000000.5
SHOW_GAIN_ADJUSTMENT
Returns the current gain peak stabilization adjustment as a number from –32767 to 32767.
This value changes dynamically when gain stabilization is enabled. See also
SET_GAIN_ADJUSTMENT.
Responses:
No adjustment.
GAIN_ADJ 00000000000
Maximum adjustment.
GAIN_ADJ 00000032767
Minimum adjustment.
GAIN_ADJ –00000032767
SHOW_GAIN_CHANNEL
Reports the current center channel for the stabilizer gain peak. See also
SET_GAIN_CHANNEL.
Responses:
Gain channel has not been set.
$C00000087<CR>
Gain channel is channel 2 (lowest possible channel).
$C00002089<CR>
...
...
Gain channel is channel 16382 (highest possible channel).
$C16382107<CR>
SHOW_GAIN_COARSE
Returns the coarse gain for the DSPEC internal amplifier. In operation, the resulting signal
gain is the product of the coarse gain, the fine gain, and the super-fine gain (used by
stabilizer). The coarse gain is returned in terms of an integer gain multiplier. This command is
available only on Model 92X MCBs.
Responses:
Coarse gain reported as 1.
$C00001089<CR>
Coarse gain reported as 2.
$C00002089<CR>
Coarse gain reported as 5.
$C00005091<CR>
46
6. COMMANDS AND RESPONSES
$C00010088<CR>
$C00020089<CR>
$C00050090<CR>
$C00100088<CR>
Coarse gain reported as 10.
Coarse gain reported as 20.
Coarse gain reported as 50.
Coarse gain reported as 100.
SHOW_GAIN_CONVERSION
This command returns the conversion gain.
Responses:
Conversion gain reported as 512 channels.
$C00512095<CR>
Conversion gain reported as 1024 channels.
$C01024094<CR>
Conversion gain reported as 2048 channels.
$C02048101<CR>
Conversion gain reported as 4096 channels.
$C04096106<CR>
Conversion gain reported as 8192 channels.
$C08192107<CR>
Conversion gain reported as 16384 channels.
$C16384109<CR>
SHOW_GAIN_FINE
Returns the current fine gain setting. See SET_GAIN_FINE.
Sample Response:
GAIN_FINE 0000000000000.5 Parameter is set to 0.5.
SHOW_GAIN_PRESET
Reports the Gauss mode stabilization preset for the gain peak. The preset represents the
minimum number of incremental counts that must be collected in any one channel of the gain
peak before the gain is evaluated by the stabilizer and potentially adjusted. See also
SET_GAIN_PRESET and CLEAR_PRESETS.
Responses:
Gain preset currently 10 counts (minimum).
$G0000000010076<CR>
Gain preset currently 11 counts.
$G0000000011076<CR>
...
...
Gain preset currently 2147483647 counts (maximum).
$G2147483647121<CR>
SHOW_GAIN_STABILIZATION
Reports the state of gain peak stabilization. See also ENABLE_GAIN_STABILIZATION and
DISABLE_GAIN_STABILIZATION.
Responses:
Gain stabilization is currently enabled.
$IT<CR>
Gain stabilization is currently disabled.
$IF<CR>
SHOW_GAIN_WIDTH
Reports the current width for the stabilizer gain peak. See also SET_GAIN_WIDTH,
SET_GAIN_CHANNEL, and SHOW_GAIN_CHANNEL.
47
DSPEC® Digital Gamma-Ray Spectrometer
Responses:
$C00001088<CR>
$C00003089<CR>
...
$C00256100<CR>
...
$C16383108<CR>
Gain width has not been set.
Gain width is 3 channels (lowest possible width).
...
Gain width is 256 channels (highest possible width in
Gauss mode).
...
Gain width is 16383 channels (highest possible width in
point mode with gain channel set to 8192).
SHOW_GATE
Reports the current mode of operation of the ADC gate input. See also SET_GATE_OFF,
SET_GATE_COINCIDENT, and SET_GATE_ANTICOINCIDENT.
Responses:
Reports the ADC gate is off or ignored.
$FOFF<CR>
Reports the ADC gate is in coincident mode.
$FCOI<CR>
Reports the ADC gate is in anticoincident mode.
$FANT<CR>
SHOW_HV
Reports the current high voltage and the status of the high voltage power supply in the form
$Dvvvvvsssssccc
Where vvvvv represents the current output voltage if the high voltage is enabled, or the rearpanel high voltage setting if the high voltage is disabled. sssss represents the status of the
high voltage bias supply as a 16-bit decimal number with the following bit definitions:
Bias Supply Polarity (0=positive, 1=negative).
Bit 0 (LSB):
Bias Supply Overload (0=overload, 1=normal).
Bit 1:
High Voltage Enabled (0=disabled, 1=enabled).
Bit 2:
Example Responses:
2000 volts, Negative, Not Overloaded, Disabled.
$D0200000003077<CR>
2000 volts, Positive, Not Overloaded, Disabled.
$D0200000002076<CR>
2000 volts, Negative, Not Overloaded, Enabled.
$D0200000007082<CR>
SHOW_INPUT [0]
Reports the state of the Sample Ready input. See also PAUSE_INPUT,
PAUSE_INPUT_HIGH, and PAUSE_INPUT_LOW.
Responses:
Sample Ready input is low.
$C00000087<CR>
Sample Ready input is high.
$C00001088<CR>
48
6. COMMANDS AND RESPONSES
SHOW_INTEGRAL [start_chan,number_of_chans]
Reports the sum of the specified group of spectral data channels. If start_chan and
number_of_chans is not provided, SHOW_INTEGRAL reports the sum of all channels in the
currently selected segment that have their ROI flag set.
Responses:
Integral reported as 0.
$G0000000000075<CR>
...
...
Integral reported as 4294967294.
$G4294967294131<CR>
Integral reported as greater than or equal to 4294967295
$G4294967295132<CR>
(maximum reportable value).
SHOW_INTEGRAL_PRESET
Reports the current ROI integral preset value. For more information about the ROI integral
preset, see SET_INTEGRAL_PRESET. See also SHOW_INTEGRAL.
Responses:
Integral preset reported as 0.
$G0000000000075<CR>
...
...
Integral reported as 4294967295.
$G4294967295132<CR>
SHOW_INTEGRAL_REMAINING
Reports the current ROI integral remaining value. For more information about the ROI
integral remaining, see SET_INTEGRAL_REMAINING. See also SHOW_INTEGRAL.
Responses:
Integral remaining reported as 0.
$G0000000000075<CR>
...
...
Integral reported as 4294967295.
$G4294967295132<CR>
SHOW_LIVE
Reports the contents of the live-time counter in units of 20 milliseconds (50 ticks per second).
See also CLEAR_COUNTERS and SET_LIVE.
Responses:
Live time reported as 0 ticks.
$G0000000000075<CR>
Live time reported as 1 tick (20 milliseconds).
$G0000000001076<CR>
...
...
Live time reported as 4294967295 ticks (over 23000 days).
$G4294967295132<CR>
SHOW_LIVE_PRESET
Reports the current live-time preset in units of 20 milliseconds (50 ticks per second). See also
CLEAR_PRESETS and SET_LIVE_PRESET.
49
DSPEC® Digital Gamma-Ray Spectrometer
Responses:
$G0000000000075<CR>
$G0000000001076<CR>
...
$G4294967295132<CR>
Live-time preset reported as disabled.
Live-time preset reported as 1 tick.
...
Live-time preset reported as 4294967295 ticks.
SHOW_LIVE_REMAINING
Reports the current live-time remaining in units of 20 milliseconds (50 ticks per second). See
also SET_LIVE_REMAINING.
Responses:
Live-time remaining reported as disabled.
$G0000000000075<CR>
Live-time remaining reported as 1 tick.
$G0000000001076<CR>
...
...
Live-time remaining reported as 4294967295 ticks.
$G4294967295132<CR>
SHOW_LLD
Shows the lower level discriminator setting. See also SET_LLD.
Responses:
The lower level discriminator is 50.
$C00050092
SHOW_LOCATION_SAMPLE
Shows the location sample number. See also SET_LOCATION_SAMPLE.
Responses:
Sample number 3.
$A003248
SHOW_MODE
Reports the current mode of operation (PHA or Sample). See also SET_MODE_PHA and
SET_MODE_SAMPLE.
Responses:
PHA mode.
$FPHA<CR>
Sample mode (InSight).
$FSAM<CR>
SHOW_MODE_STABILIZATION
Reports the current stabilization mode of operation. See also SET_MODE_POINT and
SET_MODE_GAUSS.
Responses:
$FPOINT<CR>
$FGAUSS<CR>
50
6. COMMANDS AND RESPONSES
SHOW_NETWORK_ADDRESS
Returns in a $H record the Ethernet address used by the 83905 Ethernet chip. The address is
composed of a 32-bit company portion of the address which is usually set to the ORTEC ID
(41020) followed by the address portion. See also SET_NETWORK_ADDRESS.
Responses:
$H00000410200000000016058 Company ID=41020, Address=16
SHOW_NETWORK_ALL
Responds with multiple records indicating which computers are currently connected to the
MCB via the network. See also SET_NETWORK_ALL.
SHOW_NETWORK_ID
Responds with a $F record indicating the network identifier which will be used by the MCB
for all network communication. The default host name is DSPEC-xxxx, where xxxx is the
serial number of the MCB. See also SET_NETWORK_ID.
Responses:
$FDSPEC-100
SHOW_NEXT
Used in conjunction with the SHOW_ROI command, SHOW_NEXT reports the next
continuous group of channels that have the ROI flag set. The response is of the form
$Dsssssnnnnnccc<CR>
where sssss represents an integer number that is the number of the first channel of the “next”
group of channels that all have their ROI bit set, and nnnnn represents an integer number that
is the number of channels in the group. If no more channels have their ROI bit set,
SHOW_NEXT returns a first channel of 0 and a number of channels of 0. The SHOW_ROI
command is used to report the “first” group of channels that all have their ROI bit set.
Example Responses:
Next ROI group starts at channel 1000 and is 50 channels
$D0100000050078<CR>
long.
Next ROI group starts at channel 2150 and is 150 channels
$D0215000150086<CR>
long.
No other ROI groups to report.
$D0000000000072<CR>
SHOW_OUTPUT [0]
Reports the status of the “Change Sample” output port. The output port status is reported as a
16-bit number that is either 0 or 1, depending on the level last set by a SET_OUTPUT_HIGH
or SET_OUTPUT_LOW command.
Responses:
Change Sample output currently at a low level.
$C00000087<CR>
Change Sample output currently at a high level.
$C00001088<CR>
51
DSPEC® Digital Gamma-Ray Spectrometer
SHOW_OVERFLOW_PRESET
Reports the state of the overflow preset.
Responses:
Overflow preset enabled.
$IT<CR>
Overflow preset disabled.
$IF<CR>
SHOW_PAGE
See also SET_PAGE.
Responses:
Page number 1.
$A001246
SHOW_PEAK
This command returns the contents of the ROI channel with the largest number of counts. An
ROI channel is a channel that has the ROI flag set. The maximum possible value is
2147483647, which is the maximum number of counts that can be stored in a 31-bit channel.
Responses:
Maximum count in an ROI channel is zero or no ROI
$G0000000000075<CR>
channels were found.
Maximum count in an ROI channel is 1.
$G0000000001076<CR>
...
...
Maximum count in an ROI channel is 2147483646.
$G2147483646120<CR>
Maximum count in an ROI channel is 2147483647.
$G2147483647121<CR>
SHOW_PEAK_CHANNEL
This command returns the number of the ROI channel with the largest number of counts. An
ROI channel is a channel that has the ROI flag set. The lowest number ROI channel with the
largest count is reported if more that one channel contains the largest number of counts.
Channel 16383 is the highest numbered channel in any device.
Responses:
Maximum count was found in channel 0 or no ROI channels
$C00000087<CR>
were found (see errors below).
Maximum count was found in channel 1.
$C00001088<CR>
...
...
Maximum count was found in channel 16382.
$C16382107<CR>
Maximum count was found in channel 16383.
$C16383108<CR>
SHOW_PEAK_DELAY
Reports the Peak Delay setting. See also SET_PEAK_DELAY.
Responses:
Peak Delay = 3.
$A003248
52
6. COMMANDS AND RESPONSES
SHOW_PEAK_LENGTH
Shows the Peak Length setting. See also SET_PEAK_LENGTH.
Responses:
Peak Length = 2.
$A002247
SHOW_PEAK_PRESET
Reports the value of the ROI peak preset. See SET_PEAK_PRESET for information about
the ROI peak preset.
Responses:
Peak preset disabled.
$G0000000000075<CR>
Peak preset set to 1 count.
$G0000000001076<CR>
...
...
Peak preset set to 2147483646 counts.
$G2147483646120<CR>
Peak preset set to 2147483647 counts.
$G2147483647121<CR>
SHOW_PZ
Displays the PZ setting. See also SET_PZ.
Responses:
Pole zero enabled and set to 2200.
PZ_ENA 002200
Pole zero disabled and set to 1000.
PZ_DIS 001000
SHOW_PZ_AUTOMATIC
Shows the state of the automatic PZ. See also SET_PZ_AUTOMATIC.
Responses:
Pole zero enabled.
$IT<CR>
Pole zero disabled (TRP).
$IF<CR>
SHOW_PZ_DELAY
Reports the PZ Delay setting. See also SET_PZ_DELAY.
Responses:
$C00075099
SHOW_RADIX
This command is for compatibility with other ORTEC MCBs. It always reports that the
number base radix for the WRITE command is binary.
Responses:
Number base set to binary radix.
$FBIN<CR>
SHOW_REMOTE
See also SET_REMOTE.
53
DSPEC® Digital Gamma-Ray Spectrometer
Responses:
$IT<CR>
$IF<CR>
The remote is enabled.
The remote is disabled.
SHOW_ROI
Used in conjunction with the SHOW_NEXT command, SHOW_ROI reports the first
continuous group of channels that have the ROI flag set. The response is of the form
$Dsssssnnnnnccc<CR>
where sssss represents an integer number that is the number of the first channel of the “first”
group of channels that all have their ROI bit set, and nnnnn represents an integer number that
is the number of channels in the group. The SHOW_NEXT command is used to report the
“next” group of channels that all have their ROI bit set.
Responses:
First ROI group starts at chan 1000 and is 50 channels long.
$D0100000050078<CR>
First ROI group starts at chan 2150 and is 150 channels long.
$D0215000150086<CR>
No ROI groups to report.
$D0000000000072<CR>
SHOW_ROI_SAMPLE
Displays the ROI Sample setting. See also SET_ROI_SAMPLE.
Responses:
$C00001088
SHOW_ROI_UNCERTAINTY
Reports the start channel and number of channels used in the uncertainty preset calculation.
See also SET_ROI_UNCERTAINTY.
Response:
Calculation is performed on channels 7000–7049.
$D0700000050ccc
SHOW_SEGMENT
This command is for compatibility with other ORTEC MCBs. It reports the last value that
was set with the SET_SEGMENT command. Segments have no meaning in DSPECs.
Responses:
Segment last set to 1.
$A001246<CR>
SHOW_SHAP_CUSP
Shows the Cusp Factor setting. See also SET_SHAP_CUSP.
Responses:
SHAP_CUSP 000000.99999988
54
6. COMMANDS AND RESPONSES
SHOW_SHAP_FLAT
Reports the width of the flattop in µs. See also SET_SHAP_FLAT.
Responses:
SHAP_FLAT 0000000000001.2
SHOW_SHAP_RISE
Displays the Rise Time setting in µs. See also SET_SHAP_RISE.
Responses:
SHAP_RISE 0000000000003.2
SHOW_SNUM
Responds with a $F record indicating the serial number of the MCB. See SET_SNUM.
Responses:
Serial Number = 100.
$F100
SHOW_STATUS
Returns system status information in the following format:
$Mllllllllllttttttttttaaaaahhhhhccc<CR>
where llllllllll represents the live time as returned by the SHOW_LIVE command, tttttttttt
represents the true time for the current device as returned by the SHOW_TRUE command,
aaaaa represents the active device mask as returned by the SHOW_ACTIVE_DEVICES
command, and hhhhh represents the hardware status, which is an ASCII representation of a
16 bit decimal number with the following bit definitions:
Bias Supply Polarity (0=positive, 1=negative).
Bit 0 (LSB):
Bias Supply Overload (0=overload, 1=normal).
Bit 1:
High Voltage Enabled (0=disabled, 1=enabled).
Bit 2:
Unused.
Bit 3:
Amplifier PZ’d since initialization (0=normal, 1=needs PZ’ing).
Bit 4:
Optimization since initialization (0=normal, 1=needed).
Bit 5
Unused.
Bits 6–7:
Amplifier Automatic PZ (1=Auto PZ in progress, 0=normal).
Bit 8:
Optimization (0=normal, 1=in progress).
Bit 9:
Unused.
Bits 10–14:
Reserved.
Bit 15 (MSB):
SHOW_THRESHOLD_AUTOMATIC
See also SET_THRESHOLD_AUTOMATIC.
Responses:
Automatic threshold is enabled.
$IT<CR>
Automatic threshold is disabled
$IF<CR>
55
DSPEC® Digital Gamma-Ray Spectrometer
SHOW_THRESHOLD_NEGATIVE
See also SET_THRESHOLD_NEGATIVE.
Responses:
Negative threshold is 379791.
THR_NEG 0000379791
SHOW_THRESHOLD_POSITIVE
See also SET_THRESHOLD_POSITIVE.
Responses:
Positive threshold is 126811.
THR_POS 00000126811
SHOW_THRESHOLD_SAMPLE
See also ENABLE_THRESHOLD_SAMPLE, SET_THRESHOLD_SAMPLE.
Responses:
Threshold set to 3 and disabled.
THR_DIS 00000000003
Threshold set to 5000 and enabled.
THR_ENA 00000005000
SHOW_TIME
Reports the time from the battery backed-up system clock in the form
$Nhhhmmmsssccc<CR>
where hhh represents a 3-digit integer hour (0 through 23), mmm represents a 3-digit integer
minute (0 through 59), and sss represents a 3-digit integer second (0 through 59). See also
SET_TIME, SET_DATE, and SHOW_DATE.
Example Responses:
Time returned 10:54:17 (10 hours, 54 min, 17 sec).
$N010054017052<CR>
Time returned 20:13:37 (20 hours, 13 min, 37 sec).
$N020013037050<CR>
SHOW_TIME_START
Reports the time of the last START command in the form
$Nhhhmmmsssccc<CR>
where hhh represents a 3-digit integer hour (0 through 23), mmm represents a 3-digit integer
minute (0 through 59) and sss represents a 3-digit integer second (0 through 59). See also
SET_TIME_START, SET_DATE_START, and SHOW_DATE_START.
Example Responses:
Time returned 10:54:17 (10 hours, 54 min, 17 sec).
$N010054017052<CR>
Time returned 20:13:37 (20 hours, 13 min, 37 sec).
$N020013037050<CR>
SHOW_TRUE
Reports the contents of the true-time (real-time) counter in units of 20 milliseconds (50 ticks
per second). See also CLEAR_COUNTERS and SET_TRUE.
56
6. COMMANDS AND RESPONSES
Responses:
$G0000000000075<CR>
$G0000000001076<CR>
...
$G4294967295132<CR>
True time reported as 0 ticks.
True time reported as 1 tick (20 milliseconds).
...
True time reported as 4294967295 ticks (over 23000
days).
SHOW_TRUE_PRESET
Reports the current true-time (real-time) preset in units of 20 milliseconds (50 ticks per
second). See also CLEAR_PRESETS and SET_TRUE_PRESET.
Responses:
True time preset reported as disabled.
$G0000000000075<CR>
True time preset reported as 1 tick.
$G0000000001076<CR>
...
...
True time preset reported as 4294967295 ticks.
$G4294967295132<CR>
SHOW_TRUE_REMAINING
Reports the current true time (real time) remaining in units of 20 milliseconds (50 ticks per
second). See also SET_TRUE_REMAINING.
Responses:
True time remaining reported as disabled.
$G0000000000075<CR>
True time remaining reported as 1 tick.
$G0000000001076<CR>
...
...
True time remaining reported as 4294967295 ticks.
$G4294967295132<CR>
SHOW_UNCERTAINTY
Returns the current value of the uncertainty for the peak in the uncertainty preset. See also
SET_UNCERTAINTY.
Responses:
Uncertainty of the peak is 8.5%.
UNCE 0000000000008.5
SHOW_UNCERTAINTY_PRESET
Returns the current uncertainty preset setting. See also SET_UNCERTAINTY_PRESET.
Responses:
No preset.
UNCE_PRES 000000000000000
Preset set to 8.5%.
UNCE_PRES 0000000000008.5
SHOW_VERSION
Reports the DSPEC firmware Version number in the form
Fmmmm-vvv<CR>
where mmmm is a 4-character model designator and vvv is a 3-character version designator.
57
DSPEC® Digital Gamma-Ray Spectrometer
Example Responses:
$FDSPE–002<CR>
Model DSPEC firmware Version 2 reported.
SHOW_WIDTH
Reports the maximum number of bytes that may be sent by the DSPEC to the host computer
as a result of the WRITE command. See also SET_WIDTH and WRITE.
Responses:
Width reported as 12 bytes (minimum width).
$C00012090<CR>
Width reported as 13 bytes.
$C00013091<CR>
...
...
Width reported as 512 bytes (maximum width).
$C00512095<CR>
SHOW_WINDOW
Reports the start channel and number of channels in the window of interest, in the form
$Dxxxxxyyyyyccc<CR>
where xxxxx is the start channel (0–16383) and yyyyy is the number of channels (1–16384).
See SET_WINDOW for more information about the window of interest.
Example Responses:
Window of interest reported as starting at channel 0 and
$D0000016384094<CR>
continuing for 16384 channels.
Window of interest reported as starting at channel 0 and
$D0000008192092<CR>
continuing for 8192 channels (first 1/2).
Window of interest reported as starting at channel 8192 and
$D0819208192112<CR>
continuing for 8192 channels (last 1/2).
SHOW_ZERO_ADJUSTMENT
Returns the current zero peak stabilization adjustment as a number from –32767 to 32767.
This value changes dynamically when zero stabilization is enabled. See also
SET_ZERO_ADJUSTMENT and INITIALIZE_ZERO_STABILIZATION.
Responses:
ZERO_ADJ 00000005000
ZERO_ADJ 00000000000
SHOW_ZERO_CHANNEL
Reports the center channel for the stabilizer zero peak. See also SET_ZERO_CHANNEL,
SET_ZERO_WIDTH, and SHOW_ZERO_WIDTH.
Responses:
Zero channel has not been set.
$C00000087<CR>
Zero channel is channel 2 (lowest possible channel).
$C00002089<CR>
...
...
Zero channel is channel 16382 (highest possible channel).
$C16382107<CR>
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6. COMMANDS AND RESPONSES
SHOW_ZERO_PRESET
Reports the Gauss mode stabilization preset for the zero peak. The preset represents the
minimum number of incremental counts that must be collected in any one channel of the zero
peak before the zero offset is evaluated by the stabilizer and potentially adjusted. See also
SET_ZERO_PRESET and CLEAR_PRESETS.
Responses:
Zero preset currently 10 counts (minimum).
$G0000000010076<CR>
Zero preset currently 11 counts.
$G0000000011076<CR>
...
...
Zero preset currently 2147483647 counts (maximum).
$G2147483647121<CR>
SHOW_ZERO_STABILIZATION
Reports the state of zero peak stabilization. See also ENABLE_ZERO_STABILIZATION
and DISABLE_ZERO_STABILIZATION.
Responses:
Zero stabilization is currently enabled.
$IT<CR>
Zero stabilization is currently disabled.
$IF<CR>
SHOW_ZERO_WIDTH
Reports the current width for the stabilizer zero peak. See also SET_ZERO_WIDTH,
SET_ZERO_CHANNEL, and SHOW_ZERO_CHANNEL.
Responses:
Zero width has not been set.
$C00001088<CR>
Zero width is 3 channels (lowest possible width).
$C00003089<CR>
...
...
Zero width is 256 channels (highest possible width in Gauss
$C00256100<CR>
mode).
...
...
Zero width is 16383 channels (highest possible width in point
$C16383108<CR>
mode with zero channel set to 8192).
START [seg-mask]
Starts the acquisition of spectral data. The optional segment mask is provided for
compatibility with other MCBs and may be any value from 0 to 65535 but is ignored by the
DSPEC.
Execution Warnings:
No segment selected (occurs with other warnings).
%000004073<CR>
The acquisition is already started (no changes made).
%000005074<CR>
A preset was exceeded (acquisition was not started).
%000006075<CR>
Unit not optimized since initialization.
%000008073<CR>
Amplifier not PZ’d since initialization.
%000016076<CR>
High voltage is disabled.
%000032074<CR>
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DSPEC® Digital Gamma-Ray Spectrometer
The actual response record may be a combination of any of the above records depending on
the warning conditions. For example:
Amplifier not PZ’d and high voltage disabled.
%000048081<CR>
START_OPTIMIZE
Starts optimization of PZ and flattop correction for all rise times.
START_PZADJUST_AUTO
Starts the automatic PZ process. The automatic PZ is not complete until indicated by the auto
PZ status bit. This bit is returned by the SHOW_STATUS command. Spectral data can be
corrupted if automatic PZ is initiated while a device is collecting data.
Execution Errors:
The command was attempted while the amplifier was set for
%131136084<CR>
a transistor reset preamplifier. No action was taken.
STEP_OUTPUT [0]
Causes a pulse to be output on the Change Sample output port. The level of the Change
Sample output is changed then returned to the level present when the STEP_OUTPUT
command is received. The duration of the intermediate level varies but is never less than 2 µs.
Use the SET_OUTPUT_HIGH or SET_OUTPUT_LOW commands to establish an initial
output level.
Responses:
The initial and final level on Change Sample was low.
$C00000087<CR>
The initial and final level on Change Sample was high.
$C00001088<CR>
STOP [seg-mask]
Stops the acquisition of spectral data. The optional segment mask is provided for
compatibility with other MCBs and may be any value from 0 to 65535 but is ignored.
Execution Warnings:
Acquisition already stopped (no changes made).
%000005074
STOP_OPTIMIZE
Stops the optimization in progress. The DSPEC may be in an indeterminate mode. See also
START_OPTIMIZE.
STOP_PZ_AUTOMATIC
Stops the optimization in progress. The DSPEC may be in an indeterminate mode. See also
START_PZ_AUTOMATIC.
60
6. COMMANDS AND RESPONSES
TERMINAL
Prepares the serial line for communication with a terminal. In terminal mode, text sent to the
DSPEC echoes back to the host and response records sent to the host by the DSPEC are
terminated with a carriage return and line feed. This command has no effect when sent via the
mailbox. See also COMPUTER.
TEST mask
Performs any combination of the DSPEC internal selftests where mask represents a 16-bit
integer with each bit set specifying a test as follows:
Spectral data memory test (destroys spectral data).
Bit 1:
Serial line test (serial loop-back connector required)
Bit 3:
Mailbox memory test (may cause mailbox comm error).
Bit 5:
Front-panel LED test.
Bit 6:
Execution Errors:
Spectral Data Memory or Mailbox Memory failed test.
%004016080<CR>
Serial Line failed test.
%004064083<CR>
VERIFY_BLRE blue[,inc]
Allows exploration of the legal baseline restorer time constants. It responds with the closest
legal baseline restorer time constant to blue. If inc is included, the number reported is inc
steps from the closest legal value of blue. See SET_BLRE.
Sample Response:
10 is a legal setting.
BLUE 000000000000010
Execution Errors:
The first value is incorrect.
%131128085<CR>
A value is needed.
%131132080<CR>
VERIFY_CORRECTION_FLAT corr[,inc]
Allows exploration of the flattop correction settings. It responds with the closest legal setting
to corr. If inc is included, the number reported is inc steps from the closest legal value of corr.
See SET_CORRECTION_FLAT.
Sample Response:
0.1234114 is a legal setting.
CORR_FLAT 000000.51234114
Execution Errors:
The first value is incorrect.
%131128085<CR>
A value is needed.
%131132080<CR>
VERIFY_DELAY_COLLECTION delay[,inc]
Allows the collection delay settings to be explored. It responds with the closest legal setting
to delay. If inc is included, the number reported is inc steps from the closest legal value of
delay. See SET_DELAY_COLLECTION.
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DSPEC® Digital Gamma-Ray Spectrometer
Sample Response:
DEL_COLL 0000000000001.5
Execution Errors:
%131128085<CR>
%131132080<CR>
1.5 is a legal setting.
The first value is incorrect.
A value is needed.
VERIFY_GAIN_COARSE cg[,inc]
Allows exploration of the legal coarse gain settings. It returns the closest legal coarse gain
setting to cg. If inc is included, the number reported is inc steps from the closest legal value
of cg.
Example Command and Response:
VERI_GAIN_COAR 15.1
$C00020ccc 20 is the closest coarse gain to 15.1.
VERI_GAIN_COAR 15,1
$C00050ccc 50 is one step above the closest coarse
gain to 15.
VERI_GAIN_COAR 15,–1
$C00010ccc 10 is one step below the closest coarse
gain to 15.
VERIFY_GAIN_FINE fg[,inc]
Allows the legal fine gain settings to be explored. It returns the closest legal setting to gain. If
inc is included, the number reported is inc steps from the closest legal value of fg.
Sample Response:
0.5 is a legal setting.
GAIN_FINE 0000000000000.5
VERIFY_SHAP_CUSP cusp[,inc]
Allows the cusp settings to be explored. It responds with the closest legal setting to cusp. If
inc is included, the number reported is inc steps from the closest legal value to cusp. See
SET_SHAP_CUSP.
Sample Response:
0.5 is a legal setting.
SHAP_CUSP 0000000000000.5
Execution Errors:
The first value is incorrect.
%131128085<CR>
A value is needed.
%131132080<CR>
VERIFY_SHAP_FLAT flat [,inc]
Allows exploration of the flattop width settings. It returns the closest legal setting to flat. If
inc is included, the number reported is inc steps from the closest legal value to flat. See
SET_SHAP_FLAT.
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6. COMMANDS AND RESPONSES
Sample Response:
SHAP_FLAT 0000000000001.2
Execution Errors:
%131128085<CR>
%131132080<CR>
1.2 is a legal setting.
The first value is incorrect.
A value is needed.
VERIFY_SHAP_RISE rise[,inc]
Allows exploration of the rise time settings. It responds with the closest legal setting to rise.
If inc is included, the number reported is inc steps from the closest legal value to rise. See
SET_SHAP_RISE.
Sample Response:
0.8 is a legal setting.
SHAP_RISE 0000000000000.8
Execution Errors:
The first value is incorrect.
%131128085<CR>
A value is needed.
%131132080<CR>
VERIFY_THRESHOLD_SAMPLE thresh[,inc]
Allows the threshold sample settings to be explored. It returns the closest legal setting to
thresh. If inc is included, the number reported is inc steps from the closest legal value to
thresh. See SET_THRESHOLD_SAMPLE.
Sample Response:
1005 is a legal setting.
THR 000000000001005
Execution Errors:
The first value is incorrect.
%131128085<CR>
A value is needed.
%131132080<CR>
WRITE
Starts the transmission of the spectral data in the window of interest (see SET_WINDOW
command) from the DSPEC to the host computer. The WRITE command responds with a
binary data record as follows:
#Bllcc?111122223333 ... nnnns
In this record ll represents a 16-bit binary integer that is the record length, cc represents a
16-bit binary integer that is the number of the first channel in the record, ? is an unused byte,
1111 represents a 32-bit binary integer that is the contents of the first channel in the record,
2222 represents the second channel in the record, etc., nnnn represents the nth channel in the
record, and s represents an 8-bit binary checksum of the entire record up to the checksum byte
itself.
After the DSPEC responds with a binary data record, the host computer must prompt for the
next record with one of the following handshake prompts: GO<CR>, RE<CR>, or
HA<CR>; these must be entered in uppercase letters. GO causes the next binary data record
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DSPEC® Digital Gamma-Ray Spectrometer
to be sent by the DSPEC or the % response if the last record has already been sent. RE causes
the previous binary data record to be resent exactly as it was the last time. HA causes the
WRITE command to be halted and responds with a %130131078<CR> record.
The number of channels that are sent on a binary data record depends on the record width as
set by the SET_WIDTH command and the number of channels remaining in the window of
interest to be sent. If the record is the last record to be sent, it will contain the number of
channels remaining in the window of interest. This may or may not be the same number of
channels as the previous record(s). If the record is not the last record to be sent, it will contain
as many channels as will fit without creating a binary data record that is longer than the limit
set by the SET_WIDTH command. The following formula can be used to determine the
number of channels that will be sent on a record that isn’t the last record:
CHANS
(WIDTH
4
8)
In the above formula CHANS is the integer number of channels that will be sent on the record
and WIDTH is the current record width as set by the SET_WIDTH command (maximum
value is 512 bytes).
WRITE_FILE “aabbccddeeff”
Writes a block of data to the file which was opened with the OPEN_FILE command. Each
byte of data is encoded as a two hexadecimal character. In the example above, 5 bytes are
sent. Multiple WRITE_FILE commands can be used to send a long file to the MCB.
WRITE_FILE_FLASH “aabbccddeeff”
Writes a block of data to be written to the flash memory beginning with the first byte in the
flash memory. The OPEN_FILE_FLASH command must be set before using this command.
Each byte of data is encoded as two hexadecimal characters. In the example above, 5 bytes
are sent. Multiple WRITE_FILE_FLASH commands are used to send the entire block of data.
64
INDEX
ADC gate . . . . . . . . . . . . . . . . . . . . . . . . . . 35, 48
Automatic PZ . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Change Sample . . . . . . . . . . . . . . . . . . . . . . . . . 60
Change Sample output . . . . . . . . . . . . . . . . . . . 51
Coarse gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Conversion gain . . . . . . . . . . . . . . . . . . . . . 34, 47
Device number . . . . . . . . . . . . . . . . . . . . . . . . . 45
DISABLE_GAIN_STABILIZATION . . . . . . . 27
Firmware version . . . . . . . . . . . . . . . . . . . . . . . 58
Gain channel . . . . . . . . . . . . . . . . . . . . . . . . 33, 46
Gain peak stabilization . . . . . . . . . . . . . . . . . . . 47
Gain stabilization . . . . . . . . . . . . . . . . . . . . . . . 27
Gain stabilization adjustment . . . . . . . . . . . . . . 33
Gain width . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Gauss mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
High voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Integral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Integral preset . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Overflow preset . . . . . . . . . . . . . . . . . . . 27, 28, 52
PEAK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Peak Channel . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Point mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Radix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Region-of-interest . . . . . . . . . . . . . . . . . . . . . . . 26
ROI flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Sample Ready . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Selected device . . . . . . . . . . . . . . . . . . . . . . . . . 45
Stabilization mode . . . . . . . . . . . . . . . . . . . . . . . 50
Stabilization preset . . . . . . . . . . . . . 34, 41, 47, 59
Start date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Start time . . . . . . . . . . . . . . . . . . . . . . . . . . . 40, 56
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Window of interest . . . . . . . . . . . . . . . . . . . . . . 25
Zero channel . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Zero peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Zero stabilization . . . . . . . . . . . . . . . . . . 27, 58, 59
Zero stabilization adjustment . . . . . . . . . . . . . . . 41
Zero width . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
65
DSPEC® Digital Gamma-Ray Spectrometer
66
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